closely scrutinized for application. First, when ...... drawing would be of the exact form as the primary, only containing fewer components. ...... CCD Atomy. --. --. --.
IF- 7/ :
NASA
Contractor Report 182269
G_
R89AEB208
/
Electro-Optic
for Servicing
.
Architecture
Sensors
and
Actuators in Advanced Aircraft Propulsion Systems
Final
Report
(NASA-CR-182269) ELECTRO-OPTIC ARCHITECTURE FOR SERVICING SENSORS AND ACTUATORS IN ADVANCED AIRCRAFT PROPULSION SYSTEMS Final Report, Apr. 1988 - Jan. 1989 (GE) 98 p
N93-13762
Unclas
G3/74
Prepared
b)
O.k. Poppel W. M, Glasheen G E .4 irt'ru.fl
Enghw.s
Cmllrol., Engineeri,g Operalioll Cincinnati. O/litJ 45249
June
191_9
Prepared for R,J, Baumbick. Project Manager National Aeronautics and Space Administration 21000 Brookpark Road Cleveland, Ohio 44135 Contract
NAS3-25344
NASA NN_ d41_m'_ulCs lhN¢o A_v_omm_'_
0133991
z_mmmm_
J_
i
m
Report
NO.
2. Govemmen!
A¢Clss_on
NO.
CR-182269 i,J
m
• T;_le and $_Dt,tle
June 1989
Electro-Optic Architecture for Servicing Sensors and Actuators in Advanced Aircraft Propulsion Systems
6. Plirlormlng
OrOinlZJllon
Class
G.L.
It
*, p;-0,m,n_ O_,,on
7. AulPlOrtll
C_#
R,po_No.
Poppel & W.M. Glasheen i 10.
g. Pef_(m'nmgOrgar.Zahon Nlme ina AGaress
General Electric Aircraft 1Neumann Way Evendale, Ohio 45215
WOr_
Un,!
11'.' C,QRIrlIGI
Engines
NO:
or
Grant
No.
NAS3-25344 13.
Ty_e
of
Regorl
In0
Pef,O0
Covereo
Contract Final Re_or: April 8S - January E9 NASA Lewis Research Center 21000 Brookpark Road Cleveland, Ohio 4_135
Project
Manager:
14
R.j. Baumbick,
i ;
SPonsormQ
Agency
COde
NASA Lewis Research Center 21000 Brookpark Road Cleveland, Ohio 44135
"6
ABSTRACT
¢
A detailed design of a fiber optic propulsion control system, integrating favored ._ensor_ and electro-optics architecture is presented. Layouts, schematics, and sensor lists describe an advanced fighter engine system model. Components and attributes of candidate fiber oplic sensors are identified, and evaluation criteria are used in a trade study resulting in favored sensors for each measurand. System architectural ground rules were applied to accomplish un electro-optics architecture for the favored sensors. A key result was a considerable reduction in signal conductors. Drawings, schemufics, specifications, and printed circuit board ]aw)uts describe interface.
IZ
Key
_torOS
the
($ugQlsIIlO
detailed
system
design,
C_a|$_!
(Or 1_1
application
of a planar
optical
Dy Authorts))
Fiber optic propulsion control Fiber optic sensors Electro-optic architecture Planar optic waveguide 19. SICUr,Iy
including
fl_}
i_.
Unclassified
I • FOr
5aJe
Dy
fr_e NalJonal
18.
CJ4ss;t
S_unIy
Unclassified,
system
Iof thll
DllltrtDUll_.n
$llleff_llnl
_Qe} 21.
Unclassified Tecrm,cal
Unlimited
Ir_fotmalJOO
NO.
O! pages
| Serwce
SDr'n(_f:elo.
V_rg_nli
22161
waveguide
i
T
"
2
.
ABBREVIATIONS
A8
Variable
Exhaust
Nozzle
AB
Afterburner
A/C
Aircraft
A/I
Anti-lce
CVG
Compressor
FADEC
Full Authority
F/B
Feedback
FVG
Fan Variable
LVDT
Linear
MFC
Main
NH
Compressor/High
Pressure
Turbine
NL
Fan/Low
Turbine
Speed
P5
Turbine
PLC
Power
PS3
Compressor
RVDT
Rotary
Variable
T1
Engine
Inlet
1"2_5
Compressor
T5
Low Pressure
T/C
Thermocouple
TM
Torque
VEN
Variable
VIB
Vibration
WFM
Main
WFR
Afterburner
Variable
Throat
Area
Geometry
Digital
Electronic
Control
Geometry
Variable
Differential
Transformer
Fuel Control
Pressure Discharge Lever
Speed
Pressure
Control Discharge
Pressure
Differential
Transformer
Temperature Inlet
Temperature
Turbine
Disch_lrge
Temperature
Motor
Fuel
Exhaust
Nozzle
Flow Fuel Flow
I
PRECEDING
P,_tGE BI. At'!K NOT
FII.MED
!
Table of Contents I
I
I
II
Section
Page
1.0
SUMMARY
2.0
INTRODUCTION
3.0
CURRENT FADEC PROPULSION 3.1 SensorSct Idcntification 3.2 System Schematics 3.3 Intcrrogation AcccssTimes
SYSTEM
ELECTRO-OPTICS
CRITERIA
4.0
5.0
I
EVALUATION Criteria
Evaluation
4.2
Method
of Systcm
4.3
Critcria 4.3.1 4.3.2 4.3.3
Dcscription Initial Screening Criteria A Sensor Components/Attributcs Prcfcrrcd System Principlcs
5.3
Prcfcrrcd
5.3.1 5.3.2
7.0
8.0
Trade
Study
TRADE
11 14 14
Critcria B
STUDY
14
-'5 25 27 27
Scnsors
SensorSpecifications & Block Diagrams Analog Sensor Issues
-.,) 2')
PREFERRED ARCHITECTURE DESCRIPTION 6.1 Interface Description 6.2 Harness Construction & Layout 6.3 Electro-Optics Details 6.3. I Decisions On Sharing Electro-Optics 6.3.2 Electro-Optics Schematics
34
PREFERRED ARCHITECTURE DETAILED 7.1 Top Level Asscmbllcs & Documentation 7.2 Primary.Channel Opto-Elcctronic Module 7.3 Thc Elcctro-Optic Intcgratcd Componcnt 7.3.1 Physical Description 7.3.2 Design Considerations 7.4 Analog Modules
43 J3 43
CONCLUSION
PAGE
11
Objcctives
BLANK
HOT FILMED
DESIGN
34 34
4q 4q
54 54 55
V
PRECE_NG
3 3 3 8
11
4.1.
FIBER-OPTIC SENSOR 5.1 Sensor Candidates 5.2 Tradc Study Rcsuhs
6.0
I
I
I
lira
Table of Conte_
II
Concluded I
-t
Section
Page
REFERENCES
56
BIBLIOGRAPHY
63
APPENDIX
A - Fiber-Optic
Sensor Specifications
APPENDIX
B - Discussion
On Sensor Evaluation
APPENDIX
C - Evaluation
Scores For Fiber-Optic
v1
65 Criteria
Values
Sensor Candidates
73 79
I
I
I
List of Illustrations II
III
Page
Figure 1.
Current Axis.
Propulsion
System Sensor
and Effector
Current Propulsion Specific Locations.
System Sensors,
Current
Propulsion
System Layout.
4.
FADEC
Connector
Interfaces
5.
FADEC
Electrical
6.
Current
FADEC
7.
integration
8.
Method
9.
Sensor Evaluation
Criteria Values - Sources.
10.
Sensor
Evaluation
Criteria
Values - Detectors.
11.
Sensor
Evaluation
Criteria
Values - Fibers.
12.
Sensor Evaluation
Criteria
Values - Protocols.
13.
Sensor
Criteria
Values.
14.
Sensor Evaluation
Criteria
Valucs - Transduction
15.
Sensor Evaluation
Criteria
Values - Electronics.
16.
AIternatc
17.
Fiber.Optic
18.
Example of Trade Study Score Calculation Displacemcnt Sensor.
19.
Preferrcd
.
.
- Electrical
Connections
Propulsion
System-
of System Trade
EIcctro-Optics
and Discretes
Along
Engine
- Quantities
and Internal Overall
for a Fiber-Optic
Electronic
Modules.
Sensor
_._ 10
Block Diagram.
12
System.
13
Study.
Optical
i7
Elemcnts.
18
Techniques.
"3
Locations.
Displacement
and
7
System.
Scnsor Candidates.
Fibcr-Optic
4
6
Sensor
of Components
Evaluation
Effectors,
Set Location
Using the Encoded
Sensor Block Diagram.
Grcy Scaic
I
!
I
List of Illustrations Continued [TI
II
II
I
Page
Figure
21,
24.
Preferred Fiber-Optic
Shaft Speed Sensor
Preferred Fiber-Optic
Low Range Temperature
Preferred Fiber-Optic
Vibration
Preferred Fiber-Optic
Turbine Blade Temperature
Preferred Fiber-Optic
High Range Temperature
Preferred Fiber-Optic
Mass Flow Sensor Block Diagram.
3O
Block Diagram. Sensor
Block Diagram.
31
Sensor Block Diagram. Sensor Block Diagram. Sensor
26.
Preferred
2%
FADEC
Conncctor [ntcrfaccs - Preferred Fiber-Optic
FADEC
Fibcr-Optlc Sensor Connections
31
Block Diagram.
32 32 33
F3bcr-Optic Rame Detector Sensor Block Diagram.
Preferred
Fiber-Optic
and Internal Electro-Optic
37
Harness.
31,
Secondary
32.
Electrical Power Bus for T/M's, Relays, and Solenoids.
33,
Harnesses for Fiber-Optic and Electrical Power.
_4°
Combined LowTemperature, Optics For Primary Channel
Fiber-Optic
35.
Analog Sensors
36.
T/M, Relay, and Solenoid
37.
Fiber-Optic
3_
Harncss.
39
Analog Sensors, Mixed Cable Monkoring
Shaft Speed, and Displacement of Control Module.
39.
Primary Opto-Electronic
41
42
Control
Module
Opto-Elcctronic Module
Module
Functional
Layout.
viii
4-;
Interface. ..........
Primary Channel
30
42
Electro-Optics.
Scnsor/Elcctronic
Sensors,
Sensors Electro-
Eicctro-Optic_.
38.
Modulcs
System - Overall Block Diagram.
Primary Channel Fiber-Optic Channel
System.
7:
Block Diagram.
45 46
i I
Ust of Illustrations Concluded I
Ilia
I
I
I
I
r
I
Page
Figure Electro-Optic
Architecture
41.
Electronic Module.
42.
Planar Waveguide Signals.
43.
Electro-Optic
.1.4.
Printed Circuit Analog Sensors.
45.
Blade Temperature
Printed
lntcrconncction Diagram - Primary Channel
Circuit Board Layouts for the Primary
Design
to Couple
and Route
Opto-Elcctronic
Sources/Detectors
Optical
Layouts
P.wometcr
for the Electro-Optics
Electro-Optic
tX
Module.
5o
51
Integrated Modulc Outline Drawing. Board
47
Associated
with the
52
53
D
1.0 SUMMARY
The objective of this program
was to conduct a trade study that would result in a preferred
electro-optic architecture for servicing sensors and actuators in a fiber optic propulsion control system. This was to be accomplished by evaluating fiber optic sensor modulations, connections between the sensors and the control module, and the electro-optics servicing the sensors. Following the trade study, the GE program team produced a detailed design of the preferred electro-optics
architecture.
Electro-optics which includes:
is defined
electronics
as a portion
1.
The
2.
The components and actuators
3.
The components required returned from the sensors
4.
The electronics required to produce conditioned use by Full Authority Digital Electronic Control
The
program
effort
required
of an electronics
to generate
required
comprised
optical
signals
these
signals
to distribute
to detect
propulsion
and
the following
process
to propulsion
the
modulated
electrical (FADEC)
Describe including
II.
Establish evaluation criteria for optical sensor modulations, control module, and electro-optics in the control module.
resulting
system
sensors
optical
signals
signals acceptahle computers.
a trade
study
electro-optics a detailed
based
on the
architecture
established
evaluation
for the propulsion
design of the resulting preferred
connections
for
criteria
design
integrated
the favored
fiber optic sensors
with the
resulting
in
system. electro-optics
including Level I drawings, printed circuit board layouts, component specification, and connection schematics. The
module
the sensor and actuator configuration for a current propulsion system. a physical layout and specification of interrogation access times.
preferred IV. Produce
control
tasks:
I.
III. Conduct
system
architecture. definition
with electro-optics
and
architecture,
based on propulsion control system ground rules. The number of signal conductors was significantly reduced, compared with the model electrical system. A planar optical waveguide component was identified to interface between the control module chassis connectors and some optical sources/detectors.
2.0
INTRODUCTION
Advanced aircraft propulsionsystems must meet increasingly challengingperformance requirementsand endure more rigorousenvironmentalconditions. Military goalsaredirected toward high thrust/weightratiosthat require high cycle temperatures to improve thermodynamic efficiency, and lightermaterialsto i'educeweight.The use of composite materials for weight reduction makes the control system more shsceptible to electromagnetic contamination. NASA and DoD have recognized that the use of fiber optic technology wi[! provide immunity to electromagnetic interference, and will also provide higher rates of data communication. Weight savings are expected through reduced system conductor count, innovative fiber mounting techniques, and reduced complexity. In addition, fiber optic technology may potentially provide better system performance and the ability to withstand higher environmental temperatures. In 1975 NASA began work to develop fiber optic sensors for use in aircraft propulsion systems. In 1985 a program called FOCSI (Fiber Optic Control System Integration) was jointly funded by NASA and DoD. This program identified propulsion control system sensor requirements/environments, assessed the status of fiber optic sensor and component technology, and conceived a total fiber optic, integrated propulsion/night control system. The current contract evaluates the electro-optic architecture needed to service the sensors and actuators in a propulsion system and presents a detailed design of the preferred configuration.
3.0
3.1 SENSOR
CURRENT
FADEC
PROPULSION
SYSTEM
SET IDENTIFICATION
Currently, FADEC technology is being applied to the F404 propulsion system. This application combines a single channel, all electrical, digital control (primary channel) with an analog/hydromechanical backup (secondary channel). The sensor set for the F4PA FADEC system is very similar to the standard F404-GE-400 hydro/electro/mechanical system, with the addition of certain electrical sensors and sensor redundancies, but without an afterburner section.
The
pyrometer,
F404
FADEC
propulsion
system,
including
an afterburner
section
and
a
will be used as a model for the study.
Figure 1 shows approximate positions along the engine axis of the sensor/actuator set. Figure 2 is a list of the sensors, effectors, and discretes, indicating their quantity and specific location. 3.2 SYSTEM The sensor
SCHEMATICS
following locations,
figures
describe
interfaces,
the model
FADEC
system
configuration
and groupings.
Figure 3 is a sensor and actuator layout for the model FADEC system, scale. Most components are located on the bottom front portion of the FADEC electrical connectors are associated with the following signals: C1 - Primary.
control
C2 - Secondary
control
by identifying
mode
sensors
mode
sensors
approximately engine. The
t() nine
and actuators and actuators
C3 - Afterburner sensors and actuators C4 and C5 - T5 thermocouple C6 - Electrical
power
C7 and C8 - Aircraft
from the alternator signals,
C9 - RS2.32 bus for ground Figure connector
harnesses
power,
indicators,
signals
MIL-STD-1553
bus
support
4 is a system diagram indicating and the number of conductors
monitoring sensor are also shown.
and
that go directly
the components interfacing with each FADEC required by each component. The condition
to the airframe
without
passing
through
the FADEC
WFM LVC)T TM
, Sensors Fuel Flow (Compr, Casing).,) Flame Indication (AB Duct) Pyrometer (AB Duct) • Torque Motors (9): Main Fuel Flow (MFC; 2) VEN (VEN Power Unit: Dual) FVG (FVG Actuator: Dual) AB Fuel Flow (AB Control: Dual) CVG (MFC) • Solenoids (8): Mode Transfer (MFC) AJC Fuel Shutoff No. 1 (MFC) AJC Fuel Shutoff No. 2 (MFC) CVG Reset (MFC)
Anti-Ice (AJI Valve) FADEC Fuel Shutoff (MFC) AB Solenoid (AB Control) NH Lockup (MFC)
" Relays (3): Main Ignition A (MFC) Main Ignilion B (MFC) Augmentor Ignition (MFC) Anti-Ice (AJI Valve) • Indicators (6): Oil Filter Bypass (Oil Filter) Oil Temperature (Oil Level Sensor) Mode Status (FADEC) Fuel Filter Bypass (Fuel Filter) Chip Detector (Chip Detector) i
i
Figure Z. Cun'tnt Propulsion SystemSensors,£ffectors, and Discretes- Quantities and Specific Locations.
5
]I
i
-
"2
i a m
E °_
I_ !
b
_
_o
8
Figure 5 is a diagram showing the numbers of each kind of component interfacing FADEC from the outside and the internal signal conditioning module arrangement. Figure
6 isan overall
3.3 INTERROGATION
block
diagram
ACCESS
of the FADEC
with the
system.
TIMES w
The FADEC
signalsampling periods or sensor interrogationaccess times were used inthe
electro-opticsdetaileddesign to determine multiplexing capabilities. Every I0 milliseconds. for example, allthose marked as such have their digitalvalue updated once. Every 20 milliseconds,those marked as such are updated once, while those marked I0 milliseconds are updated twice.For the mode[ FADEC system, they are as follows: Inputs: LVDT's
10 ms
T'25
20 ms
Shaft Speeds Flame Detector Oil Pressure T5 T2
10 10 I0 I0 40
Pyrometer PS3 P5 Lube Level
20 20 40 40
ms ms ms ms ms
Outputs: TM's Solenoids
10 ms 10 ms
Relays Indicators
10 ms 10 ms
ms ms ms ms
Control Chassis
Module Connectors m
Connector
Function_
Numi3er of Contacts.,=.,1 I Speed
l
w
-"
FADEC Electronic
If I
21
-_
Modules
Pulse Signal Con(:fition
Flame
3
I
Excitation
2 P_ 3 7
Oemodulalion _yrometer Excitat ion/Processing RTD Excltation/DrNer Buffer
2 LVDT's
LVDT
I Fiame 5 th/Sol
Excitation
Pulse Signal Condition _tal
•"recluencl 141
TM SolenoiO _ Relay
Drivers
,)
TICCono,*oning J
I
I
RTD ExcitationlDnver
I
I ii
|
Pulse Signal Conchhon LVDT Excltalion/Democlulahcn TM/Relay/Soleno=O Dnve I, Vibe Dirver/Buffer
Figure
5. FADEC
Electrical
Sensor
ConnecUens
and Internal
Electronic
Modules.
Seconoary Co n!rol
Condition Monitoring High Temperature
Sensor_ • Airframe
T©_ue Motors, [ Re_ys. Pmmary Solenoids Sensocs,
C3 C2
Secondary Sensors, l_orclu• Motors, R4elays, Solenoids
Nozzle Sensors, Torque Motors. Solenoids, Flame
High Temperature I Core Alternator Speed
Figure 6. Current FADEC Propulsion System- Overall Block Diagram.
10
4.0
4.1 EVALUATION An
optical
ELECTRO-OPTICS
CRITERIA sensor
EVALUATION
CRITERIA
OBJECTIVES
is defined
to include
the components
that transduce
the sensed
parameter into a modulated optical signal, the interconnection components, and the electro-optic components, as shown in Figure 7. Integration of these components results in a total sensor assembly design intended to meet specified performance requirements. As combined in an overall sensor/actuator system, additional benefits may be realized through component interaction such as multiplexing. Criteria
were
therefore
1.
The optical
2.
The
connections
3,
The
electro-optic
4.2 METHOD Figure
modulation
architecture, the criteria
the following:
by the sensors.
the sensors/actuators
architecture
TRADE
the
to evaluate
produced
between
OF SYSTEM 8 describes
electro-optics by separating method.
established
method
that
services
and the control
module.
the sensors/actuators.
STUDY used
to produce
a
preferred
propulsion
system
The purpose of the method is to reduce criteria interdependencies into small, manageable steps. Following is a description of the
Given a set of sensors/actuators in the current propulsion system, an initial screening was used to eliminate those sensor candidates that inherently are not suitable for engine application. The criteria for this process were designated Criteria A. Next, particular candidate effects of
an evaluation ranking method was applied to the remaining candidates of each sensor type, such as inlet temperature, shaft speed, displacement, etc. For each inlet temperature sensor scheme, for example, a matrix was used to-measure the its known characteristics and attributes (source type, number of fibers, etc.) on the
weighted criteria factors of reliability, for this sensor ranking were designated
maintainability, Criteria B,
cost, and weighrJvolume.
The criteria
Finally, propulsion system layouts/schematics, ground rules, and other system criteria were used together with the Criteria B ranking results and individual sensor block diagrams, to construct preferred
electro-optic
architecture
for the system.
I1
l =ri i
Interconnection Alternatives
Tramx_ction Altem_ltives
I
!
,-.
Alternatives Electro-Optic
i
,
i
I
FiKture "/. Integration
i
J
of Components
Digital Control
L
for a Fiber Optic Sensor
12
System.
i.
Sensor
_J
Candidates
In_ialSensor
!_
Screening
I
Candidate Suitable List
[
- I
i Sensor Components/ Attributes Weighted Criteria
\
t
=i v I
®
Propulsion System Grouncl Rul
Screening Criteria(_)
Se.sor _
Evaluation
I S nsorT
Sensor
Block Diagrams
e I
ank,n
e_
R
Yg_
2t".er
1
_
I
]
_Ystem _
Propu,=on _
System
l -1 System Architecture Studies
Preferred Propulsion System Architecture
Figure 8. Method of SystemTrade Study,
[3
4.3 CRITERIA
DESCRIPTION
4.3.1 Initial Screening Characteristics engine application
Criteria A
of fiber optic sensors that generhlly are inherently include: -.
unsuitable
for aircraft
D
1.
w
.
Dependency on Single-Mode Fiber. Connector tolerances required to couple 5 to 10 _m (0.2 to 0.4 mils) diameter, single-mode fiber cores are difficult to achieve. Laser diode sources rat_! to 125"C are not available. The family of optical interferometers (Mach-Zehnder, Michelson, and Sagnac) are thus eliminated. Materials and Components that are environmentally (temperature, shock, vibration) unsuitable render sensors with certain sources, detectors, transduction techniques, etc., as unsuitable. Performance.The candidate must have no features that prohibit its ability to meet specified performance requirements such as accuracy, repeatability, and time response.
Two other sensor characteristics should be noted, and while not absolute bases for ruling out a candidate, sensors having themwere closely scrutinized for application. First, when the light interface in extrinsic sensors is exposed to engine media contamination such as oil, fuel, and bird ingestion, there is a risk of signal obstruction. The use of purge air in an attempt to prevent this condition increases sensor weight and volume. Second, analog sensors with no reference are vulnerable to signal variations due to nonrepeatable connector losses, cable bends and vibration, and large temperature variation, causing loss of calibration. 4.3.2
Sensor Components/Attributes
Criteria B
The purpose of the Criteria B trade study was to produce each sensor type. It consisted of the following steps:
a ranking
of the candidates
A list of sensor components and attributes, broken down in the categories of sources, detectors, fiber protocol, optical elements, transduction technique, and electronics, were identified as shown in Figures 9 through 15. The dashed lines separate subcategories. 2.
Within each category or subcategory, the sensor components or attributes were rated from 1 to 10 using the criteria of reliability, maintainability, cost, and weight/volume on a relative basis. General aspects of these criteria are discussed below. Specific discussion is contained in Appendix B. Reliability. The sensor is expected to perform as specified lifetime. For advanced fighter engine propulsion control
14
over a given components,
for
EvaluationC_erm (Weight") Components/Attributes
MainU_nab¢_
Cost
We_hV Volume
(5.1)
(6.6)
(4.8)
00)
Pertaining to Sources
ii
A1.
IRED-Surface
Emitter
A2. A3.
IRED-Edge
i
5
9
(Bun'uss_e) Emitter
IRED-Superluminescent
ToU¢
+
7
+
5
,,
185.7
(x10)
(x5,1)
(x6.6)
(x4.e)
6
5
5
5
62.5
6
5
4
5
135.9
3
5
6
4
127.5
6
4
6
1
124.8
10
10
10
10
265.0
7
4
3
5
1342
5
4
3
4
'I094
(as for Sognocsensor) A4. AS.
Tungsten
Lamp
Xenon Lamp
o..o................o.o......I..m.oo...o.l=qo...=
A6.
..=.o
NO source
o..=.Q....
.........
(as w_h pyrometer) A7.
Two sources (for two wavelengths)
AS.
Four sOUrCeS
(" - See Rein 3, I_lfllgraph
4.3.2, exl_ining
Figure
9. Sensor
Components/Atlributes
criteria weights)
Evaluation
CHteria
Values
Evaluation
Cntena
Maintainebillty (S.1)
Cost (6.6)
- Sources.
(Weight) Weigr_U Volume (4.8)
Total
Pertaining to Detectors
Reliabillt'y (10)
91.
St PfN Photodiocle
9
5
8
5
192.3
82.
fnC,_
g
5
7
5
185.7
B3.
Si Avalanche
7
5
2
5
132.7
PIN Photodiode Photodiode
(temp. camp. circuit) B4,.
InG&,AS Ave_nche Pho_odiode (ten'_p. comp. circuit)
7
5
1
5
126.1
Be.
UV Tube
5
4
5
3
117 8
6.
3
4
3
116.1
(mclu_r_h_ voltage) B6. .I
CCDArmy ee....m.ol._m.,
o
i
ill
I..i..i.
ii
iwl.mee.lmoe
_ll.i
n
i.
i
w mae_el.i
...........
07.
Two detectors
7
5
7
3
156 1
B8.
Four detectors
6
5
6
2
134. ?
og.
Deteclor
5
5
5
2
116.1
Array
i
Figure
10. Sensor
Evaluation
Criteria
t5
Values
- Dct_tors.
I
Evaluation Critena (Weight) Componems/ANributes Pertaining to Ftbe_
Relial_llty (10)
Ma_a_al:d_ (5.t)
Cost (6,6)
Weight/ Votume (4.8)
TotJ
C1.
7
7
8
5
182.5
Polyimide Coated Silica
(not _w_J¢) C2.
Alum. Coated Silica
g
4
5
5
167.4
Co,
Gla_ (no{ radiation hard)
5
2
9
5
143.6
CA.
Uncoated Silica
7
3
5
4
137.5
C5.
Go4dCoated Silica
8
3
2
5
132.5
(no( muct_ll(o tesz_g) C6.
One fiber
9
7
8
9
200.5
C';.
Two fibers
8
5
4
8
170.3
C8,
Up to eight fibers
6
4
2
7
127 2
C9
Up to 20 fibers
4
3
t
5
859
C10.
Over 20 fibers
3
3
1
4
71 1
Fisure ! 1. Sensor Evaluation Criteria
"Values- Fiber_.
i
i
i
Evaluation Criteria (Weight) Reliability (10)
Protocol Attributes i
MlintatnId_iib/ (5.1)
Cost (6 6)
i.
WeigNU Volume (4,8)
Total
i
Ot.
Pulse Rate ot Frequency
9
7
8
5
202. S
O2.
Digital Wave, Encode (requires dif_' optics)
9
S
5
5
172.5
03.
Pulse Delay. Pulse Time. Pl'uumOilfenmco
8
5
8
S
1691
O4,
Wavelength _
8
3
S
S
152.3
OS.
O_
a
4
4
3
141.2
06.
Mod. Imen_
7
I
6
S
138.7
o_,.
ok_, _ Enco_ (h_gh_o,ed anJog ¢,c.)
7
a
3
S
129.1
O8.
Intlm,_ty Ratio
S
3
5
4
117.5
Og
fmmsicy Variot_0n
4
2
6
5
113,8
pma,t Line= or Wave.
Fillure 12. Sensor Evaluation
Criteria Values - Protocols.
16
i
ii
i
ii
i
i
Evaluation Criteria (Weight)
Components/Attributes Pertaining to Optical Elements
Maintainability (5.1)
Relial_ility (10)
l
Cost (6.6)
WeighU Volume (4.8)
Total
!
El.
Tapered Fiber
8
7
6
7
lU.9
E2
Selfoc Lens
7
5
8
5
1"72.3
E3.
Coupler, Waveguide
8
7
4
5
166.1
E4
Blackbody
8
6
4
5
161.0
E5.
Bulk Optic Lens
8
3
7
2
15i.1
E6.
Mirror (metal or glass)
8
3
7
2
151.1
El.
Coupler, Fused Taper
7
5
4
4
141.1
E8.
Grating (metal or glass)
8
3
3
3
129.5
E9
Filter, Color Separ.
5
3
6
3
119.3
El0.
Optical Modulator
5
5
4
3
116.3
E11.
Precision Optics
2
2
2
5
674
El2.
No Connector
10
1
10
g
214.3
E13.
Connector,
Single Contact
7
3
5
6
147.1
El4.
Connector,
Multi.Contact
5
2
4
2
96 2
...................................
....
........................
..........
E15.
Two Optical Elements
8
5
4
7
165.5
El6.
Four Optical Elements
7
4
3
5
1342
El7.
Eight Optical Elements
6
3
1
2
Figure 13. Sensor Evaluation Criteria Values - Optical Elements.
17
91 5
,=
i
n
i
i|l=
EvaJuatlon Criteria (Weight)
Reliability (10)
Tran sducti_m_l_;lues
i
F1.
Tolel _
_Reflection
Maintainability (5.1)
Cost (6.6)
Weight/ Volume (4.8)
ii
Total | ,i
]
8
9
7
8
2t0.5
9
2
9
9
202.8
F2.
T_'Mods.
F3.
_
_a_kled
8
7
7
7
195.5
F4.
Subciww
F_e¢l. lrlterf.
6
8
7
7
180.6
6
8
6
6
169.2
6
6
6
8
168.6
(sm ) F5.
klcm:Camxl
F6.
RumllcJoe
FT.
_,
6
5
6
7
158.7
Fs.
r--anm Er -'z
5
6
4
7
140.6
F9.
Tmm_m
3
2
8
7
126.6
F10.
Mort_*_ultor
5
4
4
6
125.6
Fll.
_
2
2
8
7
116.6
F12.
Moi_l_C_ometry
5
3
3
5
109,1
i
Decay
,(not sealed)
IEa_posed
, .ll
I
I_tl_me ]4. Sensor Evaluation
iii
Criteria Values - Transducti.n
18
i
Techniques.
Evaluation Criteria (Weight)
Components/Attributes Pertaining to Electronic Attributes
Reliability
(10)
Maintainability (5.1)
Cost (6.6)
Weight/ Volume (4.8)
Total
nl
G1. Bandwidth Under10kHz G2. Bandwidth Over10kHz G3. Bandwidth Over I MHz
9 7
6
7
5
190.8
5
5
4
147.7
6
4
4
4
126.0
G4.
Elec. Power Under 1 Wan
8
5
7
7
185.3
G5.
Elec. Power Over I Watt
5
3
4
4
110.9
G6.
Elec. Temp. Meas. Circuit
8
4
4
4
146.0
GT.
Elec. Device Heater
7
2
4
4
125,8
GS.
"rE Cooler
7
3
3
4
124.3
Gg.
Standard Analog Elec.
8
7
8
5
192,5
G10.
Synchronous
8
4
4
4
146.0
Gll.
LowNoise
5
4
5
5
127.4
4
2
3
3
84.4
Detection
andOffset
Analog Elec. G12.
Nonstandard
Voltage
------------------------.-..
....
o-.............
....
......................
G13.
Two Active Elec. Comps.
8
8
7
8
205.4
G14.
FourActive
7
7
5
7
172.3
G15.
Eight Active Elec. Comps.
6
6
5
5
147.6
G16
OverSActiveElec.
5
5
4
4
121.1
Eiec, Comps.
Comps.
Ficure 15. Sensor Evaluation CHteHa Values - Electronics.
t9
typical specified liferangesfrom 8000 hoursforthosemounted on thefanduct, to4000 hoursforthosemounted on the turbinecasing.Itisan ongoingdesign concern.Ifreliability ishigh,maintenance shouldbe low. Maintainability - Sensors are normally designed to need no calibration or adjustment once in service. Factors include _as¢ of installation and removal. Failure detection is important. Cost - This includes initial cost and costs to replace, operate, and maintain. As defined to include the transduction element, the interconnections, and the electro-optics, sensors contribute a significant percentage of the control system cost. -
.
Weight/Volume - Again, as defined, control system weight/volume. Criteria weights were attained engineers experienced in vendor the weight of 10. Weights for the on the relative attention paid to
4.
The components Section 5. i).
5.
A total score for each sensor
4.3.3 Preferred
4.3.3.1 System Ground
part of the
by averaging the results of a survey of seven designed sensor programs. Reliability. was given other criteria were judged by each engineer based each factor in a typical sensor design project.
and attributes
System
sensors are a significant
of each sensor
candidate
candidate
resulted in a ranking
were identified
(see Section 5.3).
Principles Rules
The following ground rules are applicable to GE propulsion foreseeablefutureand were appliedtothisstudy:
system architectures
1.
The electronic control module (FADEC) consists of one physical unit mounted the engine, as shown in the current propulsion system layout, Figure 3.
2.
Sensor transduction elements system layout, Figure 3.
3.
All electro.optic module.
,
(see
components
are located
as shown
are located in or attached
in the current
in the
on
propulsion
to the electronic
control
Channels of the electronic control module, primary (A) and secondary (B) for this study, share no electro-optic components and are completely isolated in the sense of failure effects. There is a separate sensor set for each channel.
2O
5.
Sharing of electro-opticcomponents withina controlschannel, thatis,A or B, must be accompanied Connector
,
by sufficient redundancy to maintain a highlyreliablesystem.
space
on the electronic
significant amount predominate. 4.3.3.2
Fiber
of interface
Number
control
clustering.
module
is limited.
A connector
There
for each
must
sensor
be a
must
not
and Multiplexing
An emerging key advantage of fiber optics is seen to be a reduction in the number of engine . harness conductors. This will reduce harness weight and could reduce the size and weight of the electronic control module. The use of multiplexing is a strong factor in the electro-optics architecture design. Multiplexing is necessary to reduce the impact (cost. weight, volume) of adding electro-optics to the control module. 4.3.3.3
limits
System
Reliability is the for a specified
interaction
have
Reliability
(References
1 and 2)
probability that the system will function as intended, within specified period of time in a specific environment. Items in series with no
a combined
reliability
equal
to the product
of the individual
reliabilities:
n
RT=
H
_ = RI ' R2" R3""
_
I
For items in parallel, the combined
reliability iscalculatedas follows: n
FIT = I -
H
(1 - R,)
I
For example, compare the reliability of a group of three tiberopticsensors,allhaving their own source and detector (setA), with a group of three sensors that use a common detector through a coupler (set B), as shown below: _=.,
,=m_ m
,=_
fro.
L. Head.,}.'-'----1
m
m.=
Conn
I
¢.=.=, _.
...r--'_--'LF_e
=m_ .roll
f=Dm_m
.r. f--=-.,L.Conn
I
e=.
k
tl
:\. /Head
I--,----1
Conn_l-iber
R A = (1 -[1
I--'---I
-(Rse ¢ • Rooup • Ro_
R a = ( 1 - [1 - ( Rco n •R_-
Re=
21
Conn
f
"Rfe"
F_"
source and
w
..=1
/!
I_d"
w
So. urc._e_j
F:_)] 3)
.Rhe =) ]3). Rcoup. nr,ce. Roe¢
uet
/
It is clear from tl_ese equations that to achieve the same relial_ility as an unmultiplexed s_vstem,the multiplexed components of a multiplexed system must be relatively superior in reliability. Murdplezing decreases the number of components but may lower the total reliability unless the pans multiplexed are relatively superior in reliability. It would not be wise Ro multiplex a rela_ unreliable component, such as a light source (current assessment). 4.3.3.4
Electro-OpUcs
LocaUons
Another major _sue is the location of the electro.optics inside the electronic control module. A key t_l guideline is to minimize the number of fiber optic connections, each of which contribute m optical circuit losses. Following are four alternatives, as also depicted _n Figure 16 with the mumbers I through 4. °
Placing tlw ¢lectro-optics in the electronic control module chassis connector receptacle backshell would require all fiber optic connectors, and somewhat high temperaturesbecause of their attachment to an outside wall.
.
.
4o
Placing the ekctro-.optics in the engine harness connector plug backshells would allow the use.of standard electrical receptacles on the electronic control module chassis. Becamse of the hot environment, applications would currently be limited to on/off biamry signals such as shaft speed or flame detection, where thermal compensatiam may not be required. Engine harness complexity and cost would substantiall_ increase, requiring electronic and fiber optic skills.
Placing tl_ ,electro-optics on a dedicated interface board (module) in the electronic control module would require fiber optic links from the chassis connector _ceptacle to the interface board. The electronic backplane interconnections would still be electronic. The electro-optic interface module could take advantage of internal cooling for increased reliability and stability. The full set ofsemsor applications could be accommodated. All electro-optics would be physically c_atralized, providing benefits in serviceability, fault detection, and multiplexing cechniques. Placing the electro-optics w/th its applicable electronic module would requ ire fiber optic links ar connections through the electronic backplane interconnection. Electro-op6cs/electronics skill mixture would be required for manufacturing and servicing.
Alternative 3 pro,d_s an environment required for current electro-optics applications, while minimizing fiber _c interconnections. It also facilitates transition from near-term engine demonstrations wlm_e the electro-optics is mounted in a separate chassis.
22
O;_IG;NAL P/_.OE"|$ OF POOR QUALITy
FADEC Control Module
Backplane -
--/. Module Boards Max Steady State 1250 to 140 ° C Brief Excursions to 215" C -
Component Temperature Max Steady State -100 ° C Brief Excursions to 125 ° C
Figure 16.Alternate Electro-Oplics Locations.
23
4.3.3.5 In current the electronic
Actuation propul_on systems, torque control module at typically
motors are mounted on actuators and driven from ± 80 rnilliamps. Solenoids are typically used to open
and close a valve using 3K)0ma/16Vdc, and relays are typically used to open and close a circuit using 30ma/14Vdc. For this contract, signals that activate these devices were considered as low level optical signaLs _ operate an optical switch. To
implement
_
optically
controlled,
electronically
powered
torque
motor,
high
temperature optical detection electronic circuitry has been demonstrated (Reference 3). GaAs, silicon carbide, and other semiconductors are possible. Electrical control of fluidic actuation is a demom_ated and acceptable technique. Therefore, for this design, actuation control uses fiber optic signals received at the actuator(s) by high temperature circuitry, that drives a torque motor,_olenoid, or relay. The optical signals use a constant frequency, varying duty cycle square _ Io represent analog level to torque motors and simply on-off signals for solenoids and relay, s. [n order to provide positive and negative signals for compatibility with existing torque motors, two colors are used. [f each
torque
m_ 0.22; gold hermetic laver to 300 u.m maximum diameter, 20 u.m minimum thickness
Size
1.25 cm inch diameter
Environment
(entire
at root; 5 cm long
sensor):
Temperature
-55 ° to 1650°C at probe -55 ° to 600"C at fiber termination -55" to 260"C fiber cable
Vibration
I0 to2000 Hz, to20 g's
Contamination
Sealedagainstfuel,oil, water, cleaningsolvents, and detergents
68
SPECIFICATION
FOR
FIBER
OPTIC
BLADE
PYROMETER
This sensor has an optical probe assembly which accepts optical energy emitted by turbine blades due to their temperature. The optical emissions are conducted to the engine control where a silicon detector is used to measure the radiation. A block diagram is shown in Figure 23. There is one pyrometer probe on the engine. The probe is permanently connected to its optical cable. The optical cable will comprise multiple fibers to enable a large enough signal to the detector and still allow reasonable cable bendingwithout an intolerably high mechanical stress in the fiber silica. The amount of optical area to carry from blade image to the detector is about I square millimeter. The magnification of the blade from the object to fiber aperture will be between I and 0.25, depending on engine configuration. Performance:
le
Blade
Temperature
540° tO 1000°C 10°C above
Accuracy Numerical
,
Range
Aperture
0.20
700°C
+ 0.01
Transmission
50% average, 0.4 to 1.1 _m; average stable within 2%, spectrum stable within 5%
Response
17 microseconds
Time
Physical: Fibers
200/240 layer
step index;
gold hermetic
to 300 _.m maximum
20 _m minimum thickness; core(s) area 1 mm Size
,
Environmen
3.0 cm diameter
diameter, total
at root
t:
Temperature
-55 ° to 1000°C at probe -55 ° to 600°C at fiber termination -55 ° to 2600C fiber cable
Vibration
10 to 2000
Contamination
Purge air available from 450 ° to 650°C for continuous clean optic
69
Hz, to 20 g's
SPECIFICATION
This sensor
has an optical
FOR
assembly
flame. The optical emissions are and re-emits longer wavelength significantly higher transmission detector is used to measure the and below There
that
level
"off."
FIBER
which
conducted energy.
OPTIC
accepts
diagram
energy
emitted
SENSOR
by the afterburner
to a fluorescent material The longer wavelengths
in silica fiber radiation. Above
A block
FLAME
which are
pilot
absorbs the UV conducted with
to the engine control, where a solid state a certain level the sensor is to indicate "on,"
is shown
in Figure
26.
is one flame sensor on the engine. The probe is permanently
connected
to its optical
cable. The optical cable will comprise multiple fibers to enable a large enough signal to the detector and still allow reasonable cable bending without an intolerably high mechanical stress in the fiber. The amount of optical area to carry from the flame image to the detector is at least one square
millimeter.
Performance:
Ii
Threshold
Flame
Hysteresis Numerical
Energy
3.3 nanojoules/sr 0.3 nanojoules/sr
Aperture
UV Transmission
0.20
+ 0.01
40% minimum at any wavelength, 0.2 to 0.3 _,m to wavelength shift device; average spectrum stable
Fluorescence
Total efficiency 30% minimum: sensitivity, 180 to 300nm
Transmission
80% at fluorescence
Response
o
stable within within 10%
Time
5%;
spectrum
1 millisecond
Physical: Fibers
Size
200/240 step index; to 300 _.m maximum
hermetic layer diameter;
20 _.m minimum
thickness.
3,0 cm diameter,
2.5 cm long
7O
o
Environmen
t:
Temperature
-55 ° to 350_C at probe -55 ° to 26ff'C fiber cable
Vibration
10 to 2000 Hz, to 20 g's
Contamination
Must meet performance with oil, fuel, water in sensing area.
71
Appendix B Discussion on Sensor Evaluation Criteria Values
DISCUSSION
APPENDIX B ON SENSOR EVALUATION
CRITERIA
VALUES
Sources In general, IRED's are the most reliable optical sources. They are solid state, about 5% electrical-to-optical efficient, and being small, they are efficiently launched into optical fibers. The amount of life ranks high to low, as seen in the literature, from surface emitter to edge emitter to superluminescent, although launch efficiency improves in the same direction because of size and NA. Some manufacturers state a life for edge emitting diodes of 10,000 hours at 1250C. At room temperature, a life of a million hours has been claimed. Although there are differences in life of the surface and edge emitter, theirs are close together, and they have about 10X the life of a laser diode at any given temperature (Reference 8). The life of a superluminescent diode is midway between those two extremes. All the solid state devices are considered resistant to the vibration levels seen in engine electronics. Cost ranges from $20 to S1000 or more from surface type to superluminescent. Device sizes are similar among the three. Xenon lamps are not made as small as IRED's and their life is not as long. They are more electrically efficient, but the plasma is relatively large and not nearly as efficiently launched into fiber. They generate EMI which needs to be shielded. They are not expensive. Their output does not change as dramatically with temperature compared to IRED's. A tungsten lamp filament needs to run at high temperature, at least 2000°K (about 1700°C) to emit near IR. They are generally not as long lived as IRED's, although some are rated at 100,000 hours at room temperature. Physically they can be small, but the source is large and poorly launched into fiber. Their output does not change as much with temperature compared with IRED's, but they are more vibration sensitive, especially as life is consumed. They are inexpensive. In general, sources are one of the weakest reliability links in the sensor architecture. Attribute A6 applies to a sensor that does not require a source such as a pyrometer or some flame sensors. Such a source is simpler and should have a higher score in the source category. compared to, for example, a high temperature Fabry Perot cavity. Attributes A7 and A8 apply to sensors that require more than one source. Detectors
(Reference
9)
The silicon PIN photodiode is commercially available with bandwidth to 100 MHz. That is enough for most of the sensor types considered in this work. Even if a fast sensor time response is not necessary, the transduction or multiplexing schemes sometimes dictate fast circuits. Time delay techniques cans easily require 100 MHz. The silicon PIN photodiode costs between $10 and $100, depending on the area and performance. It can be linear over six decades of signal level and has sensitivity from 200 to 1100 nm.
73
PRECEDING PPlGE BLA,r_K NOT FILMEO
The
silicon
avalanche
photodiode
can
be
100X
more
sensitive
than
the
PIN
type,
depending on bias voltage. Although it is nonlinear, it can also perform much faster. It is several times more expensive and usually is used with several hundred of volts bias which must be closely controlled as a function of temperature. The InGaAs avalanche photodiode behaves similarly to the silicon PIN except that its sensitivity is from 800 to 1700 nm. It is more expensive than silicon. It is also similar to the silicon avalanche photodiode, but with sensitivity from 800 to 1700 nm. Photomultipliers and electron gain devices have broad sensitivity, from 100 to I500 nm (across many types) and are superior in the UV and visual ranges. They have competitive sensitivity in IR with cooling. They are relatively expensive, require high voltages, have medium Fibers
speed,
and are of relatively
(Reference
large volume/weight.
10)
There are applications for optical cable on engine in two general zones: -55 ° to 200.C and from -55 ° to above 200.C, as high as 600.C in some temperature displacement A short
applications vary depending sensors, the pyrometric sensors, bend radius
is desirable,
on the sensor. These and the flame sensor.
but that desire
conflicts
temperatures cases. The
would
from higher
include
with life. Life models
some
show
that
a 5 to 1 proof-test-to-service-test ratio will yield life of 100,000 hours or more at elevated temperatures, depending upon n value (a measure of resistance to fiber environment). The n value is a function of such things as overcoating hermeticity, temperature, and controls during drawing. Even for smaller fibers (125 _.m silica OD) a 12-ram radius is probably the lower limit. This must be accommodated in cable and routing design. Fiber of 400 ),m core is considered a reasonable upper diameter limit. It would or require higher proof test levels. Larger
fiber size can be reliable
need
and more
to have
readily
a minimum
maintainable
radius
of at least
at the connector
degree, because connections will degrade less as tolerance is consumed. Acceptable diameters are 100 to 400 _n. Sizes from 50 to 85 _m arc more difficult to connect no life or reliability less.
benefit
For -50. to 200.C,
because
polyimide-coated
standard
silica
outer
diameters
is suitable
and
50 mm
to some fiber core and offer
are 125 _.m for 85 _.m core
relatively
inexpensive.
or
For -50.
to 400.C, aluminum-coated silica is suitable and medium expensive. For -50" to probably 650.C, gold.coated silica is suitable, but very expensive. For bundle applications and -50. to 600"C or more, uncoated silica is possible. There is at least one fiber available which has promise over the entire temperature range without a coating, but the current diameter is a nonstandard 70 u.m OD with about a 60 to 63 _,m core diameter.
74
+ : Other optical materials besides silica are possible for fiber; for example, borosilicate, sapphire, and zirconium fluoride. Very little has been reported in the literature about the life or reliability of these materials as optical fiber. They are still emerging as products. Protocols The protocols are ranked with respect to reliability and maintainability because of their resistance to environmental effects and/or the added difficulty in maintaining the system to an as-installed performance level. The direct-digital techniques are preferred because they are either on or off and the system does not need to measure the amount of light or how long it is on. Digital parallel lines are considered a superior protocol because the signals are kept separate. Wavelength encoding is considered slightly better than time delay encoding because it will be insensitive to such things as cable length differences from engine to engine and changes due to maintenance action. For multimode systems, the threat of color effect in the connectors (Fabry Perot interference) is not of concern. The next most robust protocols are those that still do not need to know how much light, such as frequency or phase measurement, when some threshold is crossed and timing begins or ends. The amount of light changes the precision because of signal to noise effects on threshold detection. Wavelength shift is similar in that the amount of light affects precision but not accuracy. Knowing a peak wavelength within a range is not as easily detected as digital spectral codes because the peak position is of interest, and it will be more susceptible to connector effects and spectral mode effects in the cable. Modulated intensity is ranked near the bottom because the amount of light is measured. It is slightly better than pure analog level because the modulation allows synchronous detection (or phase locked loop) which rejects d.c. noise, the largest noise component. The least desirable is a system which needs to know the amount of light because it will be very susceptible to many effects such as source changes, cable changes, and connector changes. However, a pyrometer, at least, has no source effects, as it has none. Optical Elements Optical elements are considered more reliable than electro-optic or electronic elements because they are passive. Added optical elements are not penalized as severely as, for example, added optical sources. It is assumed that the elements are designed and installed to resist the appropriate environment, for example, glass lenses at low temperatures to quartz and sapphire lenses at high temperatures. A component that depends on index gradation can change gradient, or filters which depend upon interference coatings will degrade in time. Connectors are not considered as reliable as, for example, a lens because the vibration is often higher and more components are involved.
75
Transduction
Techniques
The rating of transduction techniques, like protocol ratings, is intended to depend on the maturity of the technique and its inherent environmental resistance, independent of hardware used. Reflection is a simple robust technique with ]'airly low losses (although strongly dependent on distance). Any exposed reflection surface is vulnerable to contamination and will require periodic inspection. A sealed reflection system scores significantly higher for this reason. •
The Faraday effect can be susceptible toerrant magnetic fields and usually has high absorption losses. Faraday materials are expensive, The microbend technique is rated a little lower in reliability because it stresses the fiber, but is very optically efficient and relatively inexpensive. Macrobend transducers are ranked the same. Absorption change is used in some sensors,sometimes with spectral content being important. It is considered reliable and usually low cost. Fluorescence decay has considerable experience and is rated well.
•
Moire pattern is a Iossy technique, probably inexpensive.
better suited to full imaging systems, but is
•
RF signal interferometry has been demonstrated short distances (80 MHz for 4 inches).
•
Transmission,
but requires high bandwidth
sealed or unsealed, is considered better
than reflection
for
because
there are competing connector reflections. Electronics The bandwidth threshold
is seemingly low because many of the sensors return a lower
signal than commonly seen in digital fiber systems, so the g_in-bandwidth product of the electronics becomes stressed. A high speed op-amp such as 10° can see 10 of that consumed by the gain factor. Depending upon the connector arrangement, the amount of returned energy can easily be as low as 10 nanowatts when the source also degrades with high temperature and life. Because of the low energy levels from some sensors due to such things as multiple connectors required and high transducer losses, high speed circuitry is considered a liability. The detection front end must not limit speed; with small signals and high speed the development and manufacturing effort to yield satisfactory performance is high.
76
Added and ancillary devices, such as those requiring temperature control, impose a penalty. Cooling is lessefficient and more expensive than heating, and not very effective above 100°C. A nonstandard voltage such as for PM tubes, flashtubes, or avalanche photodiodes is a penalty because it is higher than the airframe or engine generated power, requiring dedicated components to step it up. Standard analog electronics would be used with, for example, a speed sensor or phase measurement where the amount of light is not to be measured. Fluorescent decay time, even though time-based, must measure light amount, as must all the analog sensors. The chief difference is cost. Synchronous detection for very small signals usesa specialized set of four op-amps to measure the energy of a chopped signal; it can be done with one monolithic component.
77
Appendix C Evaluation Scores for Fiber-Optic
Sensor Candidates
EVALUATION
•
Example
APPENDIX C FOR FIBER-OPTIC
SCORES
Calculation:
Spectrally
Encoded
Grey
SENSOR
Scale
Displacement
Components/Attributes
Rating
IRED-Edge
162.5
Source
Two Sources
134.2
Si PIN Detector
192.3
CCD
116.1
Array
Polyimide/Silica Two Fibers
Fibers
170.3
Encoding
Protocol
172.5
S¢lfoc
Lens
Metal
or Glass
Mirror
151.1
Metal
or Glass
Grating
129.5
Multicontact
Connector
96.2
Four
172.3
Elements
Optical
Sealed
Reflection
Electronic
Sensor.
182.5
Required
Wavelength
CANDIDATES
Required
Transduction
Bandwidth
Less
Electrical
Power
Less than
Standard
Analog
Electronics
More
than
Total
Average
134.2
8 Active
Electronic
195.5
than
10 kHz
1 watt
190.8 185.3 192.5
Components
121.1 158.8
79 PRECEDING
P'AGE BLANK
NOT
FILMED
Sqmw
E_ome
_ourl:ml:
Dmcz_:
IRB)-EdQe
112.S
T.
,342
Smxw.
s,m S_ Avit'CP4
,*,-.1 ....
CCO _ 20ei, czn
1tl
• OI_I:Wl F'm:
Pm?./_ki Akmmum_4ml I FdNF
111Q.I ---
ule fo 1 F;Iws
Om.W E)emem|:
Wave. E,¢o_ wine S_ Isutw Ram
_m_aN Inlentty
.........
_alm Vm .........
Seil_¢ Le_ Wll_ Cctupilr
lSll
Plm,
ta.S .-
l_.S
n
_,, o,,,, 11r_5
._
,:S4_
--
_,m_
IW=
Ir,_w O_la
IS.1
--
962
112.1 --
112,5 -_,.5
-1174
........... _16 S ......
Roi_e¢. Emo_
...........
(10 Kk(Z _.1 ke.tz
1---=7
ig0.l --
112 .S
...
_
..... -S
1523 ......
--
--
_
--
lsl
--
-.
I
... 1:!1
IU
172 3
I
--
tSt
1
47 4 ---
_;_
t47
1
147
I
11,15
_li2S
_Sla.3
_g2.3
iM
IM
--
_ll&5 ....... l_J.I
llOO
12S.0
....
-.-.
v;SI 124 3
112.6 .-
167 4
_70.3 •-
.-* 127 2'
_75 .-
tt38
.--
_M
I
iS!
t --
ltg3 _74
$
.-
IJt'S--
I -..
1St
I
...-962 ..
202 1
--
_98 5
.....
li0
1
---
lgOl
_gOl
1_0
1274
1274
.-
...
| A_rvl
--
_
1471
1471
---
121.t
IM
gl 5
,_460
-
1
i
.-
...
.....
-....
_21 I
1274 1474
'127 4 ...
•-
121 1
_41,5
Evaluatioa
I
_2 It
--leOI
147
.......
Lo_ N(_SW0ffH(
121 1
Lev_
141 1
............ --
)4lA_COml),
k_m9
--
'remp ktees_re Deuce _qmm, TE Coo_
_lll_ll
Rolerenoe
.-
_li.,
.-
.......
_o_J Sn_ Re_lec Selee F_m I_w4 ldo_oc_omew
w,m
.-
.....
............ .........
I C_'_C:_
6anew
_, IU.S
1347
_
klutl,.r_
B,Ir_
Er,,m41e
_,,v,sa,,
......... ll.l
....
I _lll'_lmtl
FJKlnmcs:
17'2 3 .........
_
,Se_, P,.Im.
Tim'_mm_-
1_.S --....
TI_M
_
_
........
P,_ OHw l_me Emmde
kk'rm'
Tr amKIu ct_ol'l
1 .-
_
_
....
2 P_ms:
Cfw
s,:,,,
Cmmm._vAm_we
Scores for Fiber Optic Displacement
8O
Sensors.
V472
SensOr Can_clate
RuotescefIca
TemswaJ
F'luomscen¢_
W_,_ge_ EnmmKI TIR
DecayT_,_
Componem,'At1_bum Source=:
IRED.Eoge
OetKtDri:
F'_e_l:
ProJoco11:
EJlcU'ortr.s:
_ml_ Analog w,e_ Retarw'ce
Fa_y Pemt W_ $44e_
tr_.$
162.5
162.5
102.3 1_.I
192.3 156_
192.3 IM.I
..... 167.4 170.3 --
11574 ...... 127.2
152.3 .w
.-202.5
152.3 ---
•-
1175
1175
••151 1
_r_l 151 1 ---
:r_._ 151 1 _51 1
-147.1 •I_.5 •-
67 4 ...... 9_2 ...... 1342
--.
•195.5
202.6 ......
t24.6 1342
Si PIN 20eM¢_Orll Dewcmr k'ray
192.3 1_16.I
Pody.tS,kca Akmvnum/Sdx:a 2 Rbers Up m I F,_s
152.S -170.3 --
Wave. E_ao_e Wave Sh_f_ P_ Rate P_se Oelay Inmnmty Raoo
-t35.9
1_.8
IREO-Suoar_rl_n. Xlmon Limp Two S(xa'ces
Fw_y Pemt W_w _ _,m Mul_moda
_92.3
192.3 -110.1
11|.1 162.5
167 4 170.3
170.3
--
1691 ..
Wave. Cout_er O_k Lira| M,'ror G.,Ung Sepw. Filter Preos, OpOcs I _tact Mul0.Corstac_ 2 Bements 4 EJem_s
--. -119.3 --1471 -. lS5.5 -.-
Tdta_ _t. Raft. Moas Souroe Rol_ec. Se-_e_ Fkme'asce Decay Morm¢_romleOr
-.-. --IM6 .--
BanOw. ,=10 KHz Power • 1 Walt Powe¢ • 1 Watl Tamp. ktnsure C)¢h'x:eHeater TE Goowr LOw NO_e/_ffiI, ot No--SUm. VOIL 4 Ac_ve Comp II ACOwl Comp. _1Acam Comp.
190JI 185.3
Tow Ave_ige Sc_,
1649
o--
o..
151.1
151 .I .oo
129.5 119.3 .w
147.1
...
06.2 168.5 .--
13_2
•-
210.5
168.6
---
190.6 IIL_.3
190.6 II5.3
•
127.4
Evaluation Scoffs
.--
962 '34 2
-.-
o. ....
.....
---
172.3 m
127.2
172.5 .o.
--169.1
11125 .--
"256
190.6 •110.9 146.0 125,0 124.3 127 4
190 6 _853 ...... ...... ...... ...... '_274
'[90 6 IS5 3
127 4
IMI4 172:3
-121 .I
-121 I
1476 ......
147 6
-154.3
152.3
180.3
152.6
150.9
for Fiber Optic Low Range Temperature
81
Sensors.
S4m_ _4aw
B_q_dy
e_ey
e_eody
Ca,A_ 12)
CarNy (3)
O_cu_oaV _aw_y (6)
Cav_y (7)
ii
i
2_ 0
Sources
No S4un:a JRED-E_
2_0 .--
O_ecton:
S, Ir_s
I_?
-lm7
--
:
PIN
40meCson; Oew_ A-W F'm:
B_c_eeV Ca_e/iS)
C4v_ 14)
132.S _272
2U.O
2¢,S.0
-1147
tl_.3 .-
,_,7
,_7
1325 1272
_32.S _27 2
_ UI m li Rmrs Up m _ I:l_s
_32.S 12"/2
P_Ixo_s:
Inllnlly vat. In.my Ram w_ S_
I _31 ..-
Omcw EJemems:
Were C4uoW gliOc0o_ Liras
-1810 _51_1
INIoConnmA_ MUI-CO,_= l_eMJ I G_
2143 -it $
2_43
T,TnS4k,_uon
Moas _
2_.1
292.1
_92.I
2_2 1
E_o:
Oalp4W cl0K_ c t Wa_ Paw_ :, 1 Wan Te,_1. _
tM.l TM.3
_900 _lB.3
_90,1 ....
_lOO
1410
Sytv=v_ous Oel. Law Na_se_Of_ 2.4c_ _. I _-Ive C4_p ,4 _sve O_lS
_2-74 20e.4
_0 14110 _27 4 2_4
_440 -_274 ....
_4_0 _440 I_7 4
Tom A_rogo Sc_e
tM.7
,i;o
,,'_o
,i;o
151
1S1.1
151.1
2143
2_43
,;",
,;',
1
,;'s
--
--
14711
..... t_4
I_4
_5
265o
--14S7
fll23 .-
_1_ 7
1347 ......
.....
_3_.S
_3_ 5
_32S
_272
_27 2
OG"'g
138 •-.--
--1t7S _S23
_t3 I .--
---
I_
i111.1
I
-
•-2_a 3 ----
_51 _ ..... 962 _3al2
962 -
202.1 •--
-_256
202 l --
.-_09 _4110 _460 _2741
_8_3 --....... '274
-_og ,4,6 0
6
_27 4
---
_Zl I
12! I
---
_2_
t_dl_
_S4 Z
_44 0
,43.7
Sensors.
147
-
,-
£vuluuUon Scores for Fiber Opd¢ Hitch Range Temperature
82
2UO
--
Ene_ _
FJ,ct _
E_,ct S4_'=
Sources:
No Source
2M.0
_.0
2iS.0
265.0
0erect'S:
Si PIN k'_s PfN CCD Atomy 20emcws
192.3 IM.7 -11.1
192.3 --....
-IU.7 --
--116,
Fm_
Unco_ 5W_cm Over 20 RI_s
137.5 71.1
1373 71.1
137.5 71.1
137.5 71 1
Pmlo¢ols:
Inl_s, ty Vu Inie_suly Rt_o
117.5 --
-113.8
_ 113.8
117,5 --
Ogbcal Bemec_cs:
Bu_kLOOMS G'ann 9 Prl_n Opocs No Conneaor 1 Cot_tact 2 B_e_s 4Ber,_m:
151 .I ..... 67.4 214.3 .... _U5 --
151 .I
IS!.1
67 4 214.3
67.4 214.3
1U.S --
_45.5 --
151 "_ 129.5 --147._ -134.2
T,'#mso'uczmt_ Techn_iue:
TramsmummoM (Not SemKt)
I_.6
t266
126.6
12S.6
Bec0"on,:s:
84m_. ),10 KI-iZ B4m_$1,• 1 Wa_ Pomr• I Wail Tom0. t4eMuro Low No_se_ffset 4 Acove Comp, 8 ACOV$Comp _dl A_v$ Comp .......
147_7 ....... 185.3 t44.0 1274 -.. 147 6
147.7
t47.7
1115.3 i460 127+4 172.3 ......
185.3 146.0 127 4 172.3
-190 O 165.3 -127.4 .-
To,,* Average Sc_e
_532
EvaluaUon
Scores
for
121 1
Fiber
152.2
Optic
Blade
83
151.8
Temperature
Sensors.
1_
.3
SOWCeS:
IRED-Edge Two Sources
162.5 134.2
162.5 --
162.5 134.2
_62.5 --
De_ecws:
,_ PIN 20mm 0esw-w
192.3 15S.1 --
t92.3 .... --
192.3
_92.3
_10.I
11e.1
AmW
F'_ers:
P_J,S;k:s 2 F'd:ers UO m 20 F;bers
182.5 170.3 --
_12.6 170.3 --
III2.S t70.3 --
182.5 -85.9
ProtocOl:
Wave. _co4e P_se Oe*ay/l";rne _g. psrj. LJnel l_me Em:_e
-16g._ .... --
-.......
172.5
--
W_ve. Cou_e_ B_k Lens Mm_ G_-,n_ _mc_ 2 I_eme_ts Eements | E_mmm_
6emlmis:
Trans_c_on Tec_n_lue:
_4_ 2 129.1
....
-151. I .... -96_ _.S ----
166.1 ......
1SIS.1
_56 1
-96.2 ...... -9_ 5
_29.S 96.2
15_ .-9G2
-g_ .5
_2 ---
Tot! ira. lien. Re_c. Sei_l Al:_moo_ Trammm Ex,_o_. Rebec, E_l:om4
--_58.7 _2_.8 ....
_9S.5 ...... ......
-_gS.5
2_0,5 ---
_. < 10 KHz 81new. > 10 I 10 KHz Power < 1 Wit1 Stan0Sr0 AnaJ 2 Ac_ve Comp
147.7 11_3 192 5 205.4
1477 _85.3 •,92S 205.4
147 7 1853 192 S 205 •
147 7 185 :92 5 205
175 0
169 2
_63 2
"61
TotaJ Average Score
Evaluation
Scores
for
Fiber
...
Optic
85
Shaft
Speed
Sensors.
'166
"
Ba_4w < 10 KHZ Power ,( t Wa_ S_dar4 A_a_. Low No,swOftse! Nonsgl_4. Volt. 4 Aco_ _p, > 8 AC_vo Comp
190 8 185.3 --127 4 --172.3 .....
190.8 185.3 _92 5 -64 4 _72.3
190 8 1853 "'" _27 • ----'21 1
Tot_ Average Score
'_62 4
:59 0
_5_ 0
Evaluation
Scores
£or Fiber
Optic
86
Fl.',me
Sensors.
162.S
162.5
192.3 I_.I
192.3 156,1
+92.3 1561
Aluf_m num/S;itr.,ll 2 F'_oers Up Io 8 F;tx_s
167.4 170.3 --
167.4
167 4
1272
1272
Proloco_s:
Inleftsaly RIllO
117.5
117,S
09DcaJ _emlL_tS:
Se+loc Lens Wive. Coupce? Bum Lens M,r Pot
172.3 166 1 -151.1
172+3 166.1 151 .I --
Sector
I
IRED-EOge
162.5
)elli¢_ocs _
S; PIN 2 De,_ors
F,b_s:
um'_l
Ejection CS;
Ft_II,
166 ...
lgJ3
"--
I Conllc! Mum.Conlac!
1471 --
-gi2
4 F..Jem ents
1342
1342
Moes S_rce Reflec. Seweo M_.G'OO4,Rd Fluotes. D_ty
-195.5 -IM.6
292.8 -"--
169 2
BlnOw+ < 10 KHz Power < I Wilt Low,, No,se_O++set 8 Ac0ve Cot_p
1908 18._3 127 4 147 6
19011 1053 _27 4 147 6
+908 +IL53 127 4 I"76
TOIiI_Average Score
1595
156 1
,55 1
Evaluation Seom
...
962 165S
for Fiber Optic Yibrallnn Sensors.
87
._
CanOoem
F,INr Motion Frequency w_ Tenl.
Temporal Phase I_fference Renec_ve
TempomJ Phase Oifferenm Ma_ew.Og_c
Csmmo'NmvAtl_l_a m Soumm:
M:IED-Sur_ce IRED-EtlOe
1t5.7 --
115.7 _
-1112.5
_s:
Si PIN 2 DeIKmnr,
1923
192.3
192.3
PWyJSili_ 2 F4ers Up m l Fd_rs
182.5 170.3 --
+12.5 170.3 --
+125 -1272
ISroDllD_S:
Pull4 RIII/FrIKI. Pulm Oelay/T_me
202.5 --
-169.1
"169.1
Oee_ EIim'm_m'.
6udk Lens Mm-or M_t-Conta_ 2 Bemenm 4 Elern4mU
-... 96.2 165.5 --
-.
1S1 1
151.1 M.2 1655 ._
151 '; 96.2 -+342
Tmmeavc_0n Tocnmgque:
Mods. Souse Fwaday Effe¢l Relic. E,tpole4
202.8 ----
--._
140.6
_. • 10KHz Power < I wan ,Standa_ Ana_ Low _Oltut 4 Ac0ve Camp. II A¢=_ Comp
190.8 +85.3 192.5 ...... 172.3 --
190.11 +e5.3 192.5 .... 147.6
147 6
To_ Average Smre
176+2
165.0
154 3
Eiu:ll_ncI:
Fir, ure
54.
EvuluaUon
Scores
for
Fiber
B8
1166
Optic
Muss
-1908 _I_3 -+27 4
Flow
Sensors.
REPORT NASA
Lewis
Research
Center
DISTRIBUTION
(50)
21000 Brookpark Rd. Cleveland, Ohio 44135 Attn: RJ. Baumbick NASA
Lewis
NASA
Tech.
Research
Ufil.
Lewis
Center
(i)
Atm:
NASA
Norm
Lewis
Center
Research
Center
Rd. 44135
Arm:
(MS 77-1)
Seng
Naval Air Propulsion 1 Code PE 32
(i)
Center
Attn: NASA
(i)
Attn:
(1)
VA 23604-5577
Bob Bolton, Lewis
Carl
AATD
Research
Lorenzo
Washington,
Bldg. Center
401
(I)
Rd. 44135
Naval Air Systems Code 933E/Andrew
Rd.
Warminster, Attn: James
(I)
21000 Brook'park Cleveland, Ohio
Center
(I)
U.S. Army SAVRT-TY-ATP Ft. Eustis,
Naval Air Development 1 Code 6012
CA 92523
Indianapolis, IN 46219-2189 Attn: Mr. Rod Katz
Trenton, NJ Attn: Ruso Vizzini
Stoet
AF Base,
Naval Avionics Center Mail Code I3/826 6000 East 21st Street
(1)
(MS 77-1)
21000 Brookpark Cleveland, Ohio Gary
(i)
(MS 7-3)
Rd 4.4135
Wenger
Mr. Larry Meyers P.O. Box 273 Edwards
Office
Research
21000 Brookpark Cleveland, Ohio
(i)
(MS 77-1)
21000 Brook'park Rd. Cleveland, Ohio 44135 Atm:
Mr. Jim Stewart P.O. Box 273 Edwards AF Base, CA 92523
(MS 77-1) Command Glista
(])
DC 20361
PA 18974 McPanland
(i)
U.S. Army SAVRT-TY-ATA
Naval
Ft. Eustis, VA 23604-5577 Attn: Joe Dickertson
(i)
Commander AFB,
Command
ELDEC Corp. P.O. Box 3006
AFWAL/POTA Wright Patterson Attn: Les Sinai
Air Systems
(1)
Code 931E/George Derderian Washington, DC 20361
Bothell,
OH 45433
WA 98041-3006
Attn: Randy
89
Morton
(1)
Te_dyne Ryan Electrx_kcs 8_ Balboa Ave.
(i)
Boeing Advanced Systems P.O. Box 3707, M/S 33-02 Seattle, WA 98124-2207 Attn: Imre Takats
(1)
(1)
Douglas Aircraft C1-E83 212-13 Lakewood Blvd.
(])
Sa_ Diego, CA (61,.@) 569-2450 Atom D. Varshneya l_l_cock & Wilcox Beeson St. Atl_son, OH _: Norris
Bcmdix-Engine
44601 E. Lewis
C.x_t_.lDivision
Long Attn:
(2)
(1)
king P.O.
(1)
Seattle, Amn:
Honeywell MICRO P.O. Box 681
(I)
(l)
Litton Poly-Scientific 1213 N. Main St. Blacksburg, Attn: Norris
(1)
VA 24060 E. Lewis
SAIC
WA 98124 Mahesh
SWITCH
Beverly Hill, FL 32665 Attn: Floyd M. Cassidy
PA 1¢_t_-_I_58 L Mc,_ma._
l_eing Electronics Fitter Optics Prodm_,'elopment P.._. Box 24969, M/S _-1_2
(1)
San Diego, CA 92138 Attn: Stan Maki
Ban:ing Electronics P.O. Box 24969, Mi_ 71_5 Scuttle, WA 98_ ,_zm: Chuck Porter
Pt_adelphia, _n: Bruce
Beach, CA 90846 Jim Findlay
General Dynamics, Space Systems P.O. Box 85990, M/S DC-8743
I_lpt. 862 71_ N. Bendix Dr. ,_t_th Bend, IN 46611.5 h:ma: Steve Emo/Erie.._ett
Helicopters Box 1685& M[_ I!_V25
Co.
(1)
10610 Campus Point Dr., San Diego, CA 92121 Attn: Bob Lebduska
M/S 45
Sundstrand - ATG, P.O. Box 7002
740E6
Red_.
11oeing Cornmerda_,_,l_lanes P.JD. Box 3707, M/S Ift_7 ,_.,_ttle, WA 98124 Amn: David Gdttit_
(i)
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(i)
Rockford, Attn: Eric
So:attic, WA 98124 Amn: Kausar Tala_
90
IL 61125 Henderson
Dept.
(l)
/\ _r
J
4_
/
i J
