Transcript L3 AS&O 2001-06-12

ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Regaining Lost Separation in a Piloted Simulation of
Autonomous Aircraft Operations
Richard Barhydt*†
Dr. Todd Eischeid
Michael Palmer*
David Wing*
*NASA
†
Langley Research Center, Hampton VA USA
Booz-Allen & Hamilton, Hampton VA USA
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Distributed Air/Ground Traffic Management (DAG-TM)
NASA working on new concept of
operations (DAG-TM): designed to
improve system capacity, airspace user
flexibility, and user efficiency through
– Sharing information related to flight
intent, traffic, and the airspace
environment
– Collaborative decision making among
all involved system participants
– Distributing decision authority to the
most appropriate decision maker
Richard Barhydt, NASA Langley Research Center
Flight
Crew
• Information
• Decision making
• Responsibility
2/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
DAG-TM Flight Operations
• Autonomous Aircraft
– Onboard Airborne Separation Assurance System that
enables flight crew to resolve traffic conflicts with
autonomous and managed aircraft and special use airspace.
– Allowed to freely maneuver subject to not creating near-term
conflicts and complying with flow management constraints.
• Managed Aircraft
– Not equipped for autonomous operations.
– Separation from other managed aircraft provided by Air
Traffic Service Provider (ATSP).
• ATSP continues to provide flight path constraints to all aircraft as
needed to meet local traffic flow management needs.
Richard Barhydt, NASA Langley Research Center
3/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Airborne Separation Assurance System (ASAS)
• Prototype system developed at NASA Langley consists of
conflict detection, prevention, and resolution.
• Normally allows safe conflict resolution long before hazard to
safe flight created.
• Non-normal events could require pilots to resolve near-term
conflicts and regain lost separation.
• ASAS must provide effective resolution guidance prior to when
TCAS issues Resolution Advisory.
Richard Barhydt, NASA Langley Research Center
4/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Potential Reduction in Separation Minimums
• NASA interested in conducting feasibility studies looking into
potential reduction in separation minimums.
– Studies suggest lower minimums likely needed to improve
capacity.
– Current minimums trace back to limitations of older radar
systems.
• Considerations for lowering separation minimums.
– Surveillance system performance – accuracy, integrity,
availability.
– Presence of flight technical errors.
– Appropriate pilot maneuver response when confronted with nearterm conflict.
Richard Barhydt, NASA Langley Research Center
5/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Experiment Goals
• Experiment conducted in NASA Langley Air Traffic Operations
Lab to address issues related to ASAS use during near-term
conflicts and potential reduction in separation minimums.
• Experiment goals:
– Evaluate effectiveness of prototype ASAS tools in enabling
pilots to safely resolve near-term conflicts.
– Compare effects of 3 and 5 NM separation zone (with 1000 ft
vertical separation) on pilot’s ability to resolve near-term
conflicts and regain lost separation.
Richard Barhydt, NASA Langley Research Center
6/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Experiment Design
• Air Traffic Operations Lab:
– Medium fidelity PC workstation-based facility.
– Capable of simultaneous operation by 8 subject pilots.
– Pilot workstations have transport aircraft model.
– Controls and displays designed to replicate MD-11.
– Traffic information superimposed on Navigation Display.
• Subjects: 16 commercial airline pilots with Airbus or MD-11
experience.
• Design: single-factor within-subjects.
– 3 or 5 NM lateral separtion standard.
– 1000 ft vertical separation standard used for both cases.
Richard Barhydt, NASA Langley Research Center
7/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Pilot Displays and Control Panels
Richard Barhydt, NASA Langley Research Center
8/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Scenario Set-up and Pilot Tasks
• All pilots flew autonomous aircraft in DAG-TM en route environment.
• Pilots could maneuver freely without contacting controller.
• Experiment focused on air-air separation assurance and did not
include a ground component.
• Pilots required to maintain required separation from other traffic and
cross downstream waypoint at Required Time of Arrival (RTA).
• Nominal flight path through 65 NM wide corridor with restricted
areas on both sides.
• Designed near-term conflict occurred 15 min into 25 min scenario.
Richard Barhydt, NASA Langley Research Center
9/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Separation and Collision Zones
•
Based on work of RTCA Airborne Conflict Management Committee
Richard Barhydt, NASA Langley Research Center
10/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Near-term Conflict Event
• Designated intruder hidden from subject pilot until just before
predicted loss of separation.
• Intruder appeared about 6 NM away at co-altitude with ownship.
• Pseudo pilots used to ensure designed conflict occurred even
after possible previous maneuver by subject pilot.
• Initial conflict geometry (location, approach angle, time to
closest approach) designed to be same for both 3 and 5 NM
separation zone cases.
• Scenario differences between 3 and 5 NM cases:
– Separation loss occurred earlier, but further from intruder for
5 NM separation zone case.
– Designed to highlight any variation in pilot performance due
to being inside or outside separation zone.
Richard Barhydt, NASA Langley Research Center
11/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Pilot Displays when Intruder Appeared
Richard Barhydt, NASA Langley Research Center
12/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
ε
Budapest June 2003
as Measure of Threat Severity
Cross section of
5 NM Separation
Zone and Ellipsoid
ε=1
ε=0
1000 ft
3 NM
5 NM
• Ellipsoid centered on intruder aircraft inscribed within cylindrical
separation zone.
• ε combines relative lateral and vertical distances between
ownship and intruder, ε = 0 at center and ε = 1 at surface.
• Has advantage over closest point of approach in that it
normalizes lateral and vertical distance based on required
separation.
Richard Barhydt, NASA Langley Research Center
13/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Performance Metrics
• Threat proximity (εmin): actual minimum ε between 2 aircraft.
• Risk mitigation (εdiff): difference between predicted ε at time
alert issued (based on current state of both aircraft) and εmin.
– Accounts for any differences that may have occurred due to
initial conflict geometry.
– Predicted εmin at time alert issued varied from 0.01 to 0.07
with overall mean across all scenarios of 0.04.
• εmin and εdiff calculated using 5 NM ellipsoid in order to
compare results between 5 NM and 3 NM separation zones.
Richard Barhydt, NASA Langley Research Center
14/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Threat Proximity
1.0
Complied with tactical guidance
Did not comply with tactical guidance
Epsilon
min
0.8
0.6
0.4
0.2
0.0
n=9 n=6
3 NM Separation
n=13 n=3
5 NM Separation
Note: Error bars represent 1 standard error of the mean.
• Lateral separation zone size did not appear to affect threat
proximity.
• Greater separation between aircraft achieved when pilots
followed tactical resolution guidance.
– Linear regression of εmin for compliance combined across
separation zone conditions shows significant differences at
 = 0.05 level.
Richard Barhydt, NASA Langley Research Center
15/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Risk Mitigation
1.0
Complied with tactical guidance
Did not comply with tactical guidance
Epsilon
diff
0.8
0.6
0.4
0.2
0.0
n=9 n=6
3 NM Separation
n=13 n=3
5 NM Separation
Note: Error bars represent 1 standard error of the mean.
• Shows same trends as threat proximity.
• εdiff does not appear to be affected by separation zone size.
• εdiff marginally larger when pilots complied with resolution
guidance.
– Linear regression of εdiff for compliance combined across
separation zone conditions shows marginal differences
(p = 0.088) (not significant at  = 0.05 level).
Richard Barhydt, NASA Langley Research Center
16/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Conclusions and Future Work (1/2)
• Pilots performed better when they followed tactical resolution
guidance.
• In order to improve compliance rate, improvements are planned
for ASAS in effort to provide better transition between ASAS and
Airborne Collision Avoidance System (ACAS).
• Incorporate TCAS design goals into tactical resolution guidance:
– Attempt to avoid crossing intruder’s altitude.
– Provide resolution that does not require ownship to change
direction if currently maneuvering.
– Allow time for each aircraft to initiate maneuver before
changing sense of resolution advisory and only reverse
sense if needed to ensure safety.
Richard Barhydt, NASA Langley Research Center
17/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Conclusions and Future Work (2/2)
• Results of this study suggest that maneuvering to avoid near
term conflict is no more difficult when required lateral separation
reduced to 3 NM.
• Prior to reducing separation minimums, Operational Safety
Assessment considering surveillance system performance and
operational effects must be conducted.
• Future studies will further investigate ASAS/ACAS integration.
• Next major DAG-TM experiment will be joint study with Ames
Research Center to look into mixed equipage operations, en
route and terminal area procedures, and air/ground
coordination.
Richard Barhydt, NASA Langley Research Center
18/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Backup Slides
Richard Barhydt, NASA Langley Research Center
19/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Tactical Conflict Detection and Resolution (CD&R)
Intruder protected zone
Minimum distance
1. Heading change
Ownship
2. Speed change
Avoidance
vector
Advised vector
Not shown: 3. vertical speed change
Protected Zone
radius = 5 nm
½h = 1000 ft
Richard Barhydt, NASA Langley Research Center
Intruder
20/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Pilot Questionnaires
•
Question
Rating Scale
Overall Mean
How intuitive was the
conflict alerting
system?
How acceptable were
the tactical
resolutions?
1: not at all intuitive →
7: very intuitive
5.0
1: not at all acceptable
→ 7: completely
acceptable
4.3
What was the level of
safety for this
scenario?
How did the conflict
management tools
affect the risk level?
1: completely unsafe
→ 7: completely safe
4.0
1: greatly increased
risk → 7: greatly
decreased risk
4.8
Pilots asked to rate decision support tools and perceived operational
safety on scale from 1 (least favorable) to 7 (most favorable).
Richard Barhydt, NASA Langley Research Center
21/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Richard Barhydt, NASA Langley Research Center
Budapest June 2003
22/18
ADVANCED AIR TRANSPORTATION TECHNOLOGIES
DISTRIBUTED AIR/GROUND-TRAFFIC MANAGEMENT
5th USA/Europe Air Traffic Management R&D Seminar
Budapest June 2003
Concept Integrates:
$,J
Mixed equipage
Operational constraints
User preferences
Cost management,
Passenger comfort
Equipage
priority
Autonomous Aircraft
Aeronautical
Operational Control
Separation
assurance
Hazard
avoidance
Fleet management
Special Use
Airspace
avoidance
Priority
rules
Managed Aircraft
Trajectory
management
Maneuver rules
Crossing
restrictions
Terminal area
Q
User-determined optimal trajectory
Richard Barhydt, NASA Langley Research Center
Traffic flow
management
Air Traffic
Service Provider
23/18