within the focus of SAAB. - ICES - The KTH Innovative ...€¦ · within the focus of SAAB. ......

Autonomy architecture aspectswithin the focus of SAAB.

Bengt-Göran Sundqvist14 January 2014

This document and the information contained herein is the property of Saab AB and must not be used, disclosed or altered without Saab AB prior written consent.


Disposition

Discouraging assessmentAutonomy levelsCritical / non critical autonomyExamples• Ground Collision Avoidance• Midair Collision avoidance

• TCAS• RPAS• Fighters

Conclusions



Filippo Tomasello; EASA

Are UAS & RPA the same?

Remotely-piloted aircraft (RPA).An aircraft whose pilot is not on board during flight

Note. – This is a subcategory of unmanned aircraftRemote pilot station (RPS).Station at which the remote pilot manages the flight of an unmanned aircraft

Unmanned aircraft. An aircraft which is intended to operate with no pilot on board

Definitions in draft UAS SG proposal for ICAO Annex 2

NO

X



Filippo Tomasello; EASA

“Aerial Torpedo” or “flying bomb”; USA, 1918

UAS are “older” than ICAN (1919)

… even by ICAN subject to

“special authorisation”to fly internationally

“Kettering Bug”

Concerns by States

Free to enter “my” national

airspace?

NO!!!!

“Flugbombe V1”Peenemünde; GE, 1944



FAA Grounds $75,000 Surveillance Drone Due to Crowded Skies (Hawaii)The state of Hawaii spent $75,000 to purchase a

drone to conduct aerial surveillance over Honolulu Harbor, but the aircraft has been sitting in storage since it was delivered last year because authorities have been prohibited from flying it.

The Federal Aviation Administration refused to give the state permission to fly the device over the harbor. The FAA told the state the drone could not be deployed in airspace near the Honolulu International Airport and Hickam Air Force Base because the skies were too crowded, according to the Hawaii Reporter.

"It works, we're maintaining it, but we just can't fly it," Harbors Division administrator Davis Yogi told the Reporter.

The state bought the unmanned drone in November 2010 before bothering to check with the FAA to get approval to fly the aircraft, and only sought permission after the local newspaper began inquiring if authorities had secured a certificate of authorization to fly the device over the harbor.



Autonomy levelsMultiple definitions• ALFUS framework (Autonomy Levels For Unmanned Systems, 10 levels

depending on environmental complexity, mission complexity and operator/pilot dependence)

• Below semantics used in GSS/ETAP (e.g. sensor vs. weapon functions)• Subsystem/functions can have different autonomy level. Depends on

requirements on human decision, Rules of Engagement.



Framework for integration of autonomy functionality

Autonomy

Mission (Tactical) Autonomy

• Is advisory• Is mission critical• Enhances mission efficiency• Contents depends on mission requirements• Lower requirements on predictability

Core AutonomySafety enhancing Autonomy

• Is commanding• Is safety critical• Contents depends on airworthiness

requirements• Predictable

”Autonomy” includes both mission critical and (flight) safety critical abilities

Mission Autonomy could thus be implemented with a lower design rigor than safety enhancing

Autonomy.

ARP4754 / RTCA-DO 178C / DO 254 Level C/D instead of Level A/B


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Ground Proximity Warning / Ground Collision Avoidance System

EFCS SC D96

AFU ARM (MKV)

NINSterrain data base

SCAN Ground profile

Auto recovery Flight path predictionMargins

MMIWarning

AFU-command

(GPW)

Note: GCAS Does not account for obstaclesEstimated AFU trajectory

Actual AFU Trajectory


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GCAS design description

Function is default offActivation• Manually by AFU-button on panel

22VU

To mitigate the risk of malfunction the AFU is inhibited:

• Take off +20 sec• Extracted landing gear • Ejected pilot• Pilot inhibition through large stick

input or button on stick of AFU-button

• At detected failures affecting function

Limitation:• AFU shall be manually turned off

during formation flight



Midair collision avoidance

Combat training

2002 Überlingen

2006 South America

LUNA (UAV) over Afghanistan

C130 & RQ-7 Shadowover Afghanistan



Safety layers

S&ACollision

Avoidance

S&ATraffic

Avoidance

S&ASituational Awareness

ATCProvides

separation

ATMStrategic conflict

managementProcedures

TA issued for TCAS equipped

RA issued forTCAS equipped Manned

See and avoidManned traffic avoidance

ProvidenceLuck

Existing layers in current airspace

Introduced for Unmanned aircraft

Auto-ACASBetween Fighters

TCAS for RPAS?



Conclusions

Autonomous aircraft not likely to be accepted in non-segregated airspace in near futureGenuine background in aviation field of • Functions with high autonomy level• Operator/pilot focus• Research of how to use increased levels of autonomy on different

system levels (including interacting UAVs)

Different design rigor for different types of autonomy• Extensive review, analysis and testing of safety critical functions with

performance requirements

Partly existing standards and praxis • however areas exists which are not covered by standardization

Balance between• Safety, Operation, Performance and Interoperability



Cooperative, coordinated CA system mandated for {>19pax or >5.7ton}Complies with ACAS II Standard (I: TA only, III: unfeasible)Consists of: Interrogator, TCAS cptr, TCAS display, (+MODE S)Sends out Interrogations to transponder equipped aircraft.Based on time stamped replies (containing the pressure altitude) the distance

is computed. Bearing ~5deg accuracy is also received (for SA only).TAU = -(range – Dmod2/range) / d(range)/dt) is computed and used together with predicted relative altitude at TAU to issue1:

• Traffic Alert (Oral only, no guidance)• Resolution Advisory (Guidance manoeuvre)

RA can be: “Adjust vertical speed”, “monitor vertical speed”, “maintain v.s.”, “Climb”/”Descend”, “Increase Climb”/”Increase Descent”, “Climb, climb NOW”/”DDN”…Ended with “Clear of conflict”

1/ Dmod, TAU and Href are tabulated as a function of own altitude.

Manned CA system: TCAS IITraffic alert and Collision Avoidance System



TCAS automated

http://www.aerospace-technology.com/news/news62606.html

Layers



Cooperative, coordinated CA system mandated for {>19pax or >5.7ton}Complies with ACAS II Standard (I: TA only, III: unfeasible)Consists of: Interrogator, TCAS cptr, TCAS display, (+MODE S)Sends out Interrogations to transponder equipped aircraft.Based on time stamped replies (containing the pressure altitude) the distance

is computed. Bearing ~5deg accuracy is also received (for SA only).TAU = -(range – Dmod2/range) / d(range)/dt) is computed and used together with predicted relative altitude at TAU to issue1:

• Traffic Alert (Oral only, no guidance)• Resolution Advisory (Guidance manoeuvre)

RA can be: “Adjust vertical speed”, “monitor vertical speed”, “maintain v.s.”, “Climb”/”Descend”, “Increase Climb”/”Increase Descent”, “Climb, climb NOW”/”DDN”…Ended with “Clear of conflict”

1/ Dmod, TAU and Href are tabulated as a function of own altitude.

Manned CA system: TCAS IITraffic alert and Collision Avoidance System

Layers

ICAO ACAS Manual (Doc 9863):• “ACAS II was not designed with the intent of being installed on tactical military (e.g. fighter aircraft) or unmanned aircraft.”• “As such, there are technical and operational issues that must be addressed and resolved prior to installing ACAS II on these types of aircraft”

All has similar performance.

Current unmanned

aircraft has quite limited

performance



Operational Concept (Summarized)Situation Awareness

Collision Avoidance

Traffic Avoidance

ATC

Intruder

UAV

UAS Pilot

Different Autonomy levels:

•TrA activated by pilot (agreed with ATCO)

• CA performed, if not aborted, ATCO is informed after activation & after ”Clear of conflict”



CA example, animation

Host

Intruder

An evasive manoeuvre – including recovery back to straight & level flight - is continually considered.

When the evasive manoeuvre prediction indicates that the last chance to resolve the situation is reached next iteration, the manoeuvre is activated automatically.



Collision avoidance manoeuvre trajectory

Collision Volume (CV)

Uncertainties(safety margin)

Host

Intruder

Closest Point of Approach (CPA)

Protected Volume (PV)

Layers

Safety/operational balance: Uncertainties accounted for resulting in timely (safe) activations and feasible sensing requirements.Fail safe: Declare emergency at failure affecting safety. Operational safety objective can be fulfilled.Generic: Aircraft specific parts contained in trajectory estimation module



Fighters: Auto ACAS concept

Intuitive is to first identify potential collision…..



Auto ACAS does not predict future collision.

It continuously optimizes coordinated escape manoeuvres. The manoeuvre is executed when these claimed spaces intersect (in time and space).Datalink Datalink

The Auto ACAS Concept



The uncertainties are represented by cones

Cone radius• ½ Wingspan• Positionuncertainty• Pred. error of trajectory

Escape maneuver: roll 120 deg/s, followed by 5g

Cones intersect

Activate the escape maneuver!Roll to the selected escape angle and apply nz

The Auto ACAS concept

The aircraft fly within the claimed space

Control is returned to the pilot

Layers

Nuisance free: High performance escape trajectories, estimated by own aircraft, optimized and coordinated between involved aircraftFail safe: System turned off at failure affecting safety. Pilot not allowed to use system as guidanceGeneric: Aircraft specific parts contained in trajectory estimation module



Airspace classes, ATC responsibilities and limitations

ClassType of flight

Separation provided Service provided Speed limitation

Radio communication requirement

Subject to an ATC clearance

A IFR only All aircraft Air traffic control service Not applicable Continuous two-way YesIFR All aircraft Air traffic control service Not applicable Continuous two-way YesVFR All aircraft Air traffic control service Not applicable Continuous two-way Yes

IFR IFR from IFRIFR from VFR Air traffic control service Not applicable Continuous two-way Yes

VFR VFR from IFR

1) Air traffic control service for separation from IFR;2) VFR/VFR traffic information (and traffic avoidance advice on request)

250 kts IAS below 3050 m (10.000ft) AMSL - FL100 Continuous two-way Yes

IFR IFR from IFRAir traffic control service, traffic information about VFR flights (and traffic avoidance advice on request)


VFR Nil IFR/VFR and VFR/VFR traffic information (and traffic avoidance advice on request)


IFR IFR from IFRAir traffic control service and, as far as practical, traffic information about VFR flights


VFR Nil Traffic information as far as practical 250 kts IAS below 3050 m (10.000ft) AMSL - FL100 No

IFR IFR from IFR as far as practical

Air traffic advisory service ; flight information service

250 kts IAS below 3050 m (10.000ft) AMSL - FL100 Continuous two-way No

VFR Nil Flight information service 250 kts IAS below 3050 m (10.000ft) AMSL - FL100 No

IFR Nil Flight information service 250 kts IAS below 3050 m (10.000ft) AMSL - FL100 Continuous two-way No

VFR Nil Flight information service 250 kts IAS below 3050 m (10.000ft) AMSL - FL100 No

F

G

B

C

D

E

Layers

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