2017 acas xu flight test - massachusetts institute of ... acas xu flight test •introduction...
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DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.
Edward Londner
5 December 2017
2017 ACAS Xu Flight Test
Sponsor: Neal Suchy, FAA AJM-233
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 2EHL 5 December 2017
UAS Airspace Operations
Detect and Avoid is a key technology to achieve integrated UAS operations
Limitations on Flight– Governmental users rely on restricted
areas, significant operational burdens for airspace access
– Civilian use restricted to small UAS within line of sight
• See-and-Avoid requirement (14 CFR 91.113)
– UAS unable to perform this function
– Use of chase aircraft and advanced coordination with ATC for temporary flight restrictions
File and Fly
– Same process as manned aircraft
– No advanced coordination required
• UAS perform Detect and Avoid– Seamlessly integrate with traffic in all
airspace classes
– Conduct operations at any altitude
– No constraints on visual conditions
TodayToday Desired FutureDesired Future
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Detect and Avoid Overview
Primary Detect and Avoid system functions:• Remain Well Clear: strategic maneuvers to maintain separation• Collision Avoidance: tactical, last-minute maneuvers to avoid a collision
Detect and Avoid (DAA) is the capability of an unmanned aircraft toremain well clear from and avoid collisions with other airborne traffic
Collision Avoidance• Warning level• Automatic response• ~40 seconds from CPA
Remain Well Clear• Caution level• Coordinate response with ATC• ~75 seconds from CPA
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Current Airborne Collision Avoidance System Traffic alert and Collision Avoidance System (TCAS)
Range Altitude Bearing
Transponder-only
TCAS
TCAS
Coordination
TCAS uses onboard surveillance and a pilot interface to provide independent collision avoidance protection
3104020
315
305
320
300
340
360
280
.818 STD
AP1
A/THR
FL 310
SPEED ALT L-NAV
7
2
Traffic Display Vertical Maneuver GuidanceCockpit Displays
Air-to-Air Surveillance
• Traffic Alert (TA)“Traffic, Traffic”
• Resolution Advisory (RA)Ex. “Descend, Descend”
• Termination of alert“Clear of Conflict”
Aural Annunciations
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Next Generation SystemNext Generation System
Next Generation Airborne Collision Avoidance System (ACAS X)
• Lincoln Advanced Concept Committee project initiated in 2008
• FAA program since 2009‒ Improve safety‒ Reduce unnecessary alerts‒ Support new platforms, airspace
operations, surveillance sources‒ Streamline development process
• Lincoln leading:‒ Threat logic ‒ Surveillance and tracking ‒ Maneuver coordination‒ Flight test planning
ACAS X supports airborne detect and avoid requirements
DynamicUncertainty
StateUncertainty
Additional Surveillance
Sources
Improvedand Flexible Threat Logic
StandardInterface
0 0 0 0 0 1 0 1 0 1 0 1 1 0 0 0 0 0 0 1 1 1 0 1 0 1 1 0 1 1 1 1 1 0 0 0 1 1 0 0 1 1 1 0 1 1 0 0 0 1 1 0 1 1 0 0 1 1 1 1 0 0 1 1 1 0 1 1 1 0 1 1 0 1 1 0 1 0 1 0 0 1 0 0 0 0 1 1 0 0 1 0 1 1 1 1 0 1 1 1 1 1 0 1 1 0 0 1 0 1 1 1 1 0 0 1 1
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 6EHL 5 December 2017
User Group
Surveillance Technology Advisories
Logic Finalized; Final MOPS
Development
ACAS XA
Current TCAS II users
(large aircraft)
Active radar supplemented
with ADS-B
Same as current TCAS II
ACAS XO
Users of specific operations
(e.g. parallel approaches)
Active radar supplemented
with ADS-B
Procedure-specific alerts for designated
intruders, global alerts for others
Under Active Development ACAS XU
Unmanned aircraftPrimary radar,
active (secondary) radar, ADS-B
Vertical and horizontal advisories
Future ConceptACAS XR
Rotorcraft TBD TBD
ACAS X Variants
Focus of this briefing
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 7EHL 5 December 2017
2014 2015 2016 2017 2018 2019 2020 2023 2024
ACAS X Development Timeline
ACAS XA,XOStandards development FAA GuidanceOp Eval Operational Use
Initial MOPScomplete
FAA TSO & AC Complete
2015 Full SystemFlight Test
ACAS XU
Flight Test 2 Initial MOPScomplete
• Viability of look-up table approach• Suitability of ACAS X RAs• Interoperability with TCAS• Legacy TCAS surveillance
Xa, Xo: August 2013 Xu: Nov-Dec 2014
R & D
2013 Proof of Concept Flight Test
2014 Proof of Concept Flight Test
• Vertical and horizontal maneuvers• ADS-B, radar surveillance• Interoperability with TCAS• Autonomous maneuvers
Xa, Xo: August 2015
• Mature logic• ACAS Xo designation• Passive surveillance validation• Enabled operational evaluation
R & D FAA GuidanceStandards development LIP
Focus ofthis briefing
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 8EHL 5 December 2017
2017 ACAS Xu Flight Test
• Introduction
• Flight test overview
• Flight test execution
• Preliminary results
• Summary
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Key Objectives:• Confirm expectations set
by modeling and simulation
• Demonstrate new features of ACAS Xu system
• Collect data in support of evaluation and follow-on development
• Integrate ACAS Xu logic onto prototype avionics and test aircraft
ACAS Xu 2017 Flight Test Objectives
• 245 scripted encounters between 2 or 3 aircraft• Edwards Air Force Base, California• June 13 – August 1, 2017
Successfully flight tested baseline ACAS Xu Detect and Avoid logic
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 10EHL 5 December 2017
Detect and Avoid Flight Test featured several firsts:1. Correlation of three surveillance sources: ADS-B, active surveillance, and primary radar
2. Optimized selection of horizontal or vertical advisories
3. Blended vertical and horizontal advisories against multiple intruders
4. ACAS Xu equipped on manned aircraft acting as surrogate UAV
5. Interoperability between ACAS Xu and Xa
6. Caution and Warning Level DAA guidance
Flight Test Statistics
Total Fly Days 12
Logged Test Flight Time 100+ aircraft-hours
Test Cards • Planned: 241• Total Flown: 245
2017 ACAS Xu Flight Test
Successful flight demonstration was a critical milestonethat will enable implementation of full DAA baseline
DAA = Detect and Avoid
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 11EHL 5 December 2017
Organizations and Roles
AFRC = Armstrong Flight Research Center
• Prototype ACAS Xu• Operator of test aircraft N3GC
• ACAS Xu integration, V&V• Analysis of results
TCAS Program Office• ACAS X sponsor• Manage development, cost,
schedule, risk
• Flight test hazard identification• Safety support
• Prototype ACAS Xu• Operator of test aircraft N6754H
• Ikhana integrationand hardware support
AFRC*• Responsible test organization• Operator of test UAS Ikhana• Develop flight test objectives,
success criteria, schedule, analysis plan
• Develop threat and surveillance logic
• Develop and test encounter scenarios
• Develop test card automation software
• Coordinate participating organizations
• Coordinate data collection, disseminate collected data
• Coordinate and conduct flight test analysis
• Document results
• Develop flight test objectives, success criteria, schedule, analysis plan
• Develop threat and surveillance logic
• Develop and test encounter scenarios
• Develop test card automation software
• Coordinate participating organizations
• Coordinate data collection, disseminate collected data
• Coordinate and conduct flight test analysis
• Document results
Lincoln LaboratoryLead Organization
• Risk tracking• Documentation
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 12EHL 5 December 2017
Surveillance and Tracking Module (STM)
• Correlation Tracker– Developed by FAA– Best Source Selection
• Fusion Tracker– Developed by Honeywell
Interrogation, Reply1030/1090 MHz
1090ES ADS-B
Primary Air-to-Air Radar*
SurveillanceSources
– Guidance bands– Caution and warning
level guidance
Turn Left, heading 340
ACAS Xu architecture is adaptable to diverse UAS platforms and performance
* Radar designed by General Atomics
ACAS Xu Architecture
Threat Resolution Module (TRM)
• Detect and Avoid Alerting– Caution and warning
advisories– Suggestive guidance
bands– Intelligent selection of
horizontal or vertical advisories
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2017 ACAS Xu Flight Test
• Introduction
• Flight test overview
• Flight test execution
• Preliminary results
• Summary
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 14EHL 5 December 2017
ACAS Xu Flight Test Overview
1090ES ADS-B
TCAS, ACAS Xa, ACAS Xu
• 245 scripted encounters• 12 encounter categories• Edwards Air Force Base,
June 13 – August 1, 2017• Emphasis on system
configuration changes
14
Critical Facts
• Surveillance inputs• Prototype manufacturer• Ownship performance• Coordination rank• Response to advisories
System Configurations
TCAS II, ACAS Xa, ACAS Xu, Mode C
• 1090ES ADS-B
• 1030/1090 Active Surveillance
• Primary Air-to-Air Radar(General Atomics)
Surveillance SourcesPrimary target
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 15EHL 5 December 2017
Flight Test Aircraft
N6754H
N6754HOperator: L3-ACSSC90 King AirACAS Xa, Xu, Mode C
IkhanaOperator: NASA ArmstrongMQ-9 Predator BACAS Xu (Primary Ownship)
N3GCOperator: HoneywellC90 King AirTCAS II, ACAS Xa
N3GC
Ikhana
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 16EHL 5 December 2017
• Typically two minutes long
• Pre-flight M&S to develop and validate cards
Priorities Category #
DemonstrateACAS Xu Features
Deliberate Alerts 85
Deliberate Alerts with Turns 21
Remain Well Clear 24
Level-off Blunders 19
Multi-threat Encounters 10
Operational Relevance
500’ VFR/IFR 14
1000’ IFR/IFR 14
Descending Overtakes 18
Collect Data
Holding Patterns 3
General Atomics 4
Surveillance 20
Multi-threat Surveillance 13
Total 245
Scripted Encounters
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 17EHL 5 December 2017
Test Card DA-72
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 18EHL 5 December 2017
Flight Test Corridor
Edwards AFB
Restricted Area
• Restricted airspace near Edwards Air Force Base (AFB)
• Ikhana limited to shaded region during testing
• Temporary partial airspace losses frequent due to other research activities
• Contingencies in place to reduce impact of airspace losses
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 19EHL 5 December 2017
Flight Test Corridor
• Test area (red) a subset of restricted area R-2515
• Manned intruders permitted to operate outside of restricted area
• Typical test aircraft speed: 180 knots (3 nmi / minute)
12 n
mi
35 nmi
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 20EHL 5 December 2017
Flight Test Corridor
• Test area (red) a subset of restricted area R-2515
• Manned intruders permitted to operate outside of restricted area
• Typical test aircraft speed: 180 knots (3 nmi / minute)
150 waypoints used during flight test
12 n
mi
35 nmi
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 21EHL 5 December 2017
Flight Test Corridor
N6754H N3GCIkhana
“Worms” are 90 seconds long
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Data Collection
• All data successfully collected
• Critical data sources included ACAS Xu TRM and STM recordings, truth data
• TRM and STM recordings– Analysis of threat and surveillance logics
– Simulation of flown encounters using recorded surveillance data
– Encounter playback with alternate logics
• Truth data– Differential or WAAS GPS
– Validation of surveillance models
– Surveillance quality analysis
– Encounter plotting
TRM = Threat Resolution ModuleSTM = Surveillance and Tracking Module
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 23EHL 5 December 2017
2017 ACAS Xu Flight Test
• Introduction
• Flight test overview
• Flight test execution
• Preliminary results
• Summary
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 24EHL 5 December 2017
Achievements
• Achieved test objectives
• Collected all data
• ACAS Xu performed as expected
• Demonstrated new system features
• Demonstrated multiple vendor implementations of system logic
• Demonstrated system performance against multiple intruder types
• Demonstrated coordination between ACAS Xu and TCAS II
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 25EHL 5 December 2017
Dual Horizontal ResponseTest Card DA-72
IkhanaN6754H
TurnRight
Clear ofConflict
TurnRight
Clear ofConflict Turn
RightTurnRight
Distance East (nmi)-6 -4 -2 0 2 4 6 8
Dis
tanc
e N
orth
(nm
i)
-1.5
-1.0
-0.5
-0
0.5
1.0
1.5
2.0
2.5IkhanaN6754H
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 26EHL 5 December 2017
Issues Requiring Analysis
Surveillance and Tracking Module
• Surveillance source switching
• Active surveillance tracker lag– Causing horizontal reversals during response scenarios
• False targets, tracks from General Atomics radar
• Comparison of correlation and fusion trackers
Threat Resolution Module
• Undesired horizontal reversals
• Ambiguity in suggestive bands
• Advisories issued against false radar targets
• Path crossing horizontal advisories
• Differences in ACAS Xu behavior between Ikhana and N6754H
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 27EHL 5 December 2017
Surveillance Source SwitchingTest Card DA-26
Intruder True Position (no alert)
Intruder Position Uncertainty (95%)
Switch from ADS-B to active
surveillance
LC L
L
C Climb Advisory (warning)
Turn Left Advisory (caution)
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 28EHL 5 December 2017
Next Steps
• Ongoing analysis of flight test results– Validation of modeling and simulation
– Investigation of observed issues
• Full DAA baseline implementation (early 2018)– Next version of system logic
– Resolution of undesired behaviors observed during 2017 Flight Test
• Flight test with Lincoln Laboratory Small UAS Test Bed (Summer 2018)– Parameter scaling to emulate large UAS flight testing
– Relaxed aircraft separation constraints
• Limited Implementation Program (2022)– Operational evaluation of ACAS Xu with Navy Triton aircraft
– UAS equipped with Xu in unrestricted airspace
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 29EHL 5 December 2017
Summary
• Lincoln Laboratory is leading development of Detect and Avoid (DAA) system ACAS Xu– Enable unrestricted UAS flight in national airspace– Logic adaptable to diverse UAS platforms
• ACAS Xu 2017 Flight Test demonstrated mature DAA logic, including intelligent selection of advisories based on ownship performance, surveillance, and encounter geometry
• Data from flight test enables validation of models, analysis of observed behavior, real encounters for ongoing system development
• Success of 2017 Flight Test enables full DAA baseline implementation in early 2018
DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.This work is sponsored by the Federal Aviation Administration under Air Force Contract #FA8721-05-C-0002. Opinions, interpretations, recommendations and conclusions are those of the author and are not necessarily endorsed by the United States Government.
Thank you! Questions?Email address: [email protected]
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 31EHL 5 December 2017
Acknowledgements
Group 42Brandon AbelJeremy AmundsonRod ColeEmilie CowenMatt EdwardsIan JessenJames KeefeErik KirsheyJ.P. LaPlanteD. Evan MakiRobert MossWes OlsonMichael OwenAdam PankenGregg ShoultsEmily SimonsJerry StankiewiczTom TellerRandy Wiken
Partnering Institutions• ACSS• Aurora Innovations• General Atomics• Honeywell• Johns Hopkins University
Applied Physics Laboratory• MITRE Corporation• NASA Armstrong
Technical CommunicationsChet Beals
FAA TCAS Program OfficeSponsor: Neal Suchy
Lincoln Laboratory Air Traffic Control Workshop 20172017 ACAS Xu Flight Test - 32EHL 5 December 2017
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Distribution Statement A: Approved for public release; distribution is unlimited.
This material is based upon work supported by the Federal Aviation Administration under Air Force Contract No. FA8721-05-C-0002 and/or FA8702-15-D-0001. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Federal Aviation Administration.
© 2017 Massachusetts Institute of Technology.
Delivered to the US Government with Unlimited Rights, as defined in DFARS Part 252.227-7013 or 7014 (Feb 2014). Notwithstanding any copyright notice, U.S. Government rights in this work are defined by DFARS 252.227-7013 or DFARS 252.227-7014 as detailed above. Use of this work other than as specifically authorized by the U.S. Government may violate any copyrights that exist in this work.