On the design of UAS horizontal separation maneuvers Enric Pastor - - PowerPoint PPT Presentation

Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work

On the design of UAS horizontal separation maneuvers

Enric Pastor Marc Pérez-Batlle Pablo Royo Raul 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 Assurance Aims at keeping minimum separation distance between aircraft and potential intruders. Typically responsibility of the ATC. Collision Avoidance Aims at preventing imminent collision in case

• f loss of separation.

Procedural Air Traffic Management Self Separation Cooperative Collision Avoidance Non-cooperative Collision Avoidance

Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work Some concepts...

Unmanned Aircraft Systems & Applications UAS UAS applications are increasing worldwide. Lack of regulation basis. Unconventional Flight Plans Flight plans more complex than point-to-point. UAS will loiter over certain areas of interest beyond the rigid nature of the airspace where they

• perate.

Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work Some concepts...

UA vs. Airliner Performance comparison UAS may have poorer flight performance than commercial airliners

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 comparison UAS may have poorer flight performance than commercial airliners

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 UAS mission. Significant performance differences between UA and airliners may lead separation 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 conflict geometry that takes into account these dissimilarities. Apply latency and turn limitation aspects to the proposed separation maneuvers in order to validate them.

Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work Assumptions and Geometry definition

1

Introduction Some concepts... Main goals

2

Geometry Assumptions and Geometry definition Taxonomy definition

3

Maneuvers Catalog

4

Turn limitation and latency Latency Turn limitations

5

Conclusions & Further Work Conclusions & Further work Questions

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 Requirements For ADS-B systems, the required acquisition range for a minimum alert time is 5 min. Therefore, acquisition range must remain constant regardless the conflict geometry. Coverage ADS-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 50 100 10 20 30 40

Separation [NM] ∆h [deg]

tc = 2 min tc = 10 min −100 −50 50 100 10 20 30 40

Separation [NM] ∆h [deg]

tc = 2 min tc = 10 min

a) b) β β

Minimum Separation for: = 45º, v = 170 kt, u = 500 kt Minimum Separation for: = 45º, v = 300 kt, u = 500 kt

−100 −50 50 100 10 20 30 40

Separation [NM] ∆h [deg]

tc = 2 min tc = 10 min −100 −50 50 100 10 20 30 40

Separation [NM] ∆h [deg]

tc = 2 min tc = 10 min

a) b) β β

Minimum 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 aerial

systems" 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

Δh

β

E Eext

Time for dmin

dmin

Δh

β

E Eext

Time for dmin

β

Eext E E dmin Time for dmin

Minimum Separation

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 on both UA speed and time to conflict tc. But...in which manner? and...When the UA could resume normal navigation?

UAS Detection Boundary 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 oblique separation maneuver has to be replaced with back/forward ones?

150 200 250 300 5 10 15 20 Beta [deg] Speed [kt]

Feasible beta angle for Oblique Maneuver according to speed of the UAS and Time to Conflict Separation Target = 3 NM

tc Feasible Maneuver Unfeasible Maneuver tc= 10 min = 2 min 150 200 250 300 5 10 15 20 25 30 35 Beta [deg] Speed [kt]

Feasible beta angle for Oblique Maneuver according to speed of the UAS and Time to Conflict Separation Target = 5 NM

tc tc Feasible Maneuver Unfeasible Maneuver = 10 min = 2 min

Time to dmin When the UA could resume navigation on

• blique separation

maneuvers?

10 20 30 40 50 60 70 80 90 3 3.5 4 4.5 5 ∆ h[º] Time to dmin [min] vuas = 300 kt vuas = 150 kt 10 20 30 40 50 60 70 80 90 4 6 8 10 12 14 ∆ h[º] Time to dmin [min] vuas = 150 kt vuas = 300 kt

a) b)

Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work Latency

Latency issues Assumptions

Conflict detection will be done 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 solution

td, tex, tnet are effectively bounded. Use of predicted positions of both the UA and the intruder.

Enroute Surveillance Services Remote Piloting Centre Cooperative Aircraft ACAS ADS-B Separation Command Conflict Detection BLOS Relay Conflict Detection Conflict Detection Ground Services Secondary Radar ABS-C Secondary Radar ABS-C Separation Command

td tnet tre

LOS Link

tex

Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work Turn limitations

Scheme & Results

dmin

β

Roll time Decition & latency Roll time Decition & latency

Intruder Trajectory Separation Trajectory Minimum Separation Target Turn Initiation Turn Completed Minimum Separation

A A B B

T

Reverse Turn

C

S M S M As seen by the pilot Maneuver initiated t t 90 95 100 105 110 115 120 125 130 135 140 1 2 3 4 5 [deg] dmin [NM]

Minimum Separation Distance vs. Target Separation: 5 NM = 15º vuav = 300 kt vint = 500 kt β β α

ta = 35 seg ta = 30 seg ta = 5 seg ta = 0 seg

Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work Conclusions & Further work

Conclusions & Further work Conclusions

A 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 coarse trajectory prediction. The impact caused by turn limitation is bounded to certain geometries.

Further work

Full automation of the decision process for a realistic range of aircraft performances.

Introduction Geometry Maneuvers Turn limitation and latency Conclusions & Further Work Questions

Questions?