Post on 25-Jun-2020
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
On the design of UAS horizontal separationmaneuvers
Enric Pastor Marc Pérez-Batlle Pablo RoyoRaul Cuadrado Cristina Barrado Xavier Prats
Universitat Politècnica de Catalunya (Barcelona-Tech)
2nd SESAR Innovation Days, 2012
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Some concepts...
Separation Assurance & Collision Avoidance
Separation AssuranceAims at keeping minimum separation distance betweenaircraft and potential intruders.Typically responsibility of the ATC.
Collision AvoidanceAims at preventingimminent collision in caseof loss of separation.
Procedural
Air Traffic Management
Self Separation
CooperativeCollision Avoidance
Non-cooperativeCollision Avoidance
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Some concepts...
Unmanned Aircraft Systems & Applications
UASUAS applications are increasing worldwide.Lack of regulation basis.
Unconventional Flight Plans
Flight plans more complexthan point-to-point.UAS will loiter over certainareas of interest beyondthe rigid nature of theairspace where theyoperate.
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Some concepts...
UA vs. Airliner
Performance comparisonUAS may have poorer flight performance than commercialairliners
Performance Parameter Unmanned Aircraft Manned Aircraft
Cruise airspeed ↓↓↓ ↑↑↑
Rate of climb ↓↓↓ ↑↑↑
Cruise altitude ≈ ≈
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Some concepts...
UA vs. Airliner
Performance comparisonUAS may have poorer flight performance than commercialairliners
Performance Parameter Unmanned Aircraft Manned Aircraft
Cruise airspeed ↓↓↓ ↑↑↑
Rate of climb ↓↓↓ ↑↑↑
Cruise altitude ≈ ≈
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Main goals
Research Goals
Motivation
Conventional separation maneuvers may have a negative impact on the UASmission.Significant performance differences between UA and airliners may leadseparation maneuvers more complex.
Objectives
Model scenarios where a UA enters in conflict with a much faster airplane.Establish a taxonomy of UA separation maneuvers as a function of the conflictgeometry that takes into account these dissimilarities.Apply latency and turn limitation aspects to the proposed separation maneuversin order to validate them.
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Assumptions and Geometry definition
1 IntroductionSome concepts...Main goals
2 GeometryAssumptions and Geometry definitionTaxonomy definition
3 ManeuversCatalog
4 Turn limitation and latencyLatencyTurn limitations
5 Conclusions & Further WorkConclusions & Further workQuestions
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Assumptions and Geometry definition
Assumptions and initial geometry definition
Initial assumptions
Only UAS is deviated and its heading change ∆h is performed instantaneously.Aircraft are moving at constant speed.No latency in UAS communications are considered.Intruder position and velocity are know by the UAS via ADS-B.
Symbol Definition
A Airliner initial position
B UA initial position
C Conflict Position (4-D)
v Airliner velocity (∈ [300, 600] kt)
u UA velocity (∈ [150, 300] kt)
β Conflict angle
∆h Heading change (∈ [−90, 90]◦)
d0 Initial separation distance
d Current separation distance
d0 Δh
C C'
d
v·t
u·t
A
B
β
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Assumptions and Geometry definition
ADS-B
RequirementsFor ADS-B systems, the required acquisition range for aminimum alert time is 5 min.Therefore, acquisition range must remain constantregardless the conflict geometry.
CoverageADS-B antenna radiation pattern is not omnidirectional.
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Taxonomy definition
Time to conflict and heading change analysis.
Forward conflict (β = 180◦)
Separation Minima
∆h for 170 kt ∆h for 300 kt
tc [minutes] tc [minutes]
2 5 10 2 5 10
3 NM 35◦ 15◦ 10◦ 20◦ 10◦ 5◦
5 NM 55◦ 25◦ 15◦ 30◦ 15◦ 10◦
10 NM N/A 45◦ 25◦ 65◦ 25◦ 15◦
Backward conflict (β = 0◦)
Separation Minima
∆h for 170 kt ∆h for 300 kt
tc [minutes] tc [minutes]
2 5 10 2 5 10
3 NM 40◦ 15◦ 10o 25◦ 10◦ 5◦
5 NM N/A 25o 15o N/A 15◦ 10o
10 NM N/A N/A 25◦ N/A 50◦ 15◦
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Taxonomy definition
Time to conflict and heading change analysis. Other β.
−100 −50 0 50 1000
10
20
30
40
Sep
arat
ion
[NM
]
∆h
[deg]
tc
= 2 min
tc
= 10 min
−100 −50 0 50 1000
10
20
30
40
Sep
arat
ion
[NM
]
∆h
[deg]
tc
= 2 min
tc
= 10 min
a) b)
β βMinimum Separation for:= 45º, v = 170 kt, u = 500 kt
Minimum Separation for:= 45º, v = 300 kt, u = 500 kt
−100 −50 0 50 1000
10
20
30
40
Sep
arat
ion
[NM
]
∆h
[deg]
tc
= 2 min
tc
= 10 min
−100 −50 0 50 1000
10
20
30
40
Sep
arat
ion
[NM
]
∆h
[deg]
tc
= 2 min
tc
= 10 min
a) b)
β βMinimum Separation for= 90º, v = 170 kt, u = 500 kt
Minimum Separation for= 90º, v = 300 kt, u = 500 kt
M. Perez-Batlle, et al. "Evaluation of separation strategies for unmanned aerialsystems" 5th ICRAT. Berkeley, CA (USA): EUROCONTROL / FAA, May 2012.
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Catalog
Catalog of separation maneuvers
β
Δh
Eext
E
D
Eext
dmin
Δhβ
E
Eext
Time for dmin
dmin
Δh
β
E
Eext
Time for dmin
β Eext
EE
dmin
Time for dmin
MinimumSeparation
dmin
Forward &Backward
Oblique Lateral
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Catalog
Maneuver selection criterion
The selection of the most effective maneuver depends onboth UA speed and time to conflict tc . But...in whichmanner? and...When the UA could resume normalnavigation?
UAS DetectionBoundary tc = 5min
0o
45o
90o
180o
135o
225o
270o
315o
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Catalog
Maneuver selection results
β threshold
When obliqueseparation maneuverhas to be replaced withback/forward ones?
150 200 250 3000
5
10
15
20
Bet
a [d
eg]
Speed [kt]
Feasible beta angle for Oblique Maneuveraccording to speed of the UAS and Time to Conflict
Separation Target = 3 NM
tc Feasible
Maneuver
UnfeasibleManeuver
tc= 10 min
= 2 min
150 200 250 3000
5
10
15
20
25
30
35
Bet
a [d
eg]
Speed [kt]
Feasible beta angle for Oblique Maneuveraccording to speed of the UAS and Time to Conflict
Separation Target = 5 NM
tc
tc
FeasibleManeuver
UnfeasibleManeuver
= 10 min
= 2 min
Time to dmin
When the UA couldresume navigation onoblique separationmaneuvers?
0 10 20 30 40 50 60 70 80 903
3.5
4
4.5
5
∆ h[º]
Tim
e to
dm
in[m
in]
vuas
= 300 kt
vuas
= 150 kt
0 10 20 30 40 50 60 70 80 904
6
8
10
12
14
∆ h[º]
Tim
e to
dm
in[m
in]
vuas
= 150 kt
vuas
= 300 kt
a) b)
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Latency
Latency issues
AssumptionsConflict detection will bedone on-board the UAS(td, tex).LOS/BLOS communications(different tnet for each case).UA pilot on the decision loop(tre).Non-negligible latency.
Proposed solutiontd, tex, tnet are effectivelybounded.Use of predicted positions ofboth the UA and theintruder.
Enroute SurveillanceServices Remote Piloting Centre
CooperativeAircraft ACAS
ADS-B
SeparationCommand
ConflictDetection
BLOSRelay
ConflictDetection
ConflictDetection
Ground Services
SecondaryRadarABS-C
SecondaryRadarABS-C
SeparationCommand
td
tnet
tre
LOSLink
tex
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Turn limitations
Scheme & Results
dmin
βRoll timeDecition & latency
Roll timeDecition & latency
IntruderTrajectory
SeparationTrajectory
MinimumSeparation
Target
TurnInitiation
TurnCompleted
MinimumSeparation
A
A
B
B
T
ReverseTurn
CS M
S
M
As seenby the pilot
Maneuverinitiated
t
t
90 95 100 105 110 115 120 125 130 135 1400
1
2
3
4
5
[deg]
d min
[NM
]
Minimum Separation Distance vs. Target Separation: 5 NM
= 15º vuav
= 300 kt vint
= 500 kt
β
β
α
ta = 35 segta = 30 seg ta = 5 seg
ta = 0 seg
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Conclusions & Further work
Conclusions & Further work
ConclusionsA taxonomy of UAS separation maneuvers has been addressed.Turn limitation and latency issues have been applied.Latency impact on separation conflicts may be minimized by means of coarsetrajectory prediction.The impact caused by turn limitation is bounded to certain geometries.
Further workFull automation of the decision process for a realistic range of aircraftperformances.
Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work
Questions
Questions?