Table Of ContentA Multi-Operator Simulation for Investigation of
Distributed Air Traffic Management Concepts
Mark E. Peters, Mark G. Ballin]" John S. Sakosky _
Hampton, VA 23666
needed for their development and assessment.
An overview of the simulation architecture is
Abstract then provided with explanations of the design
choices that were made. Elements of the future
This paper discusses the current development of
an air traffic operations simulation that supports airspace system represented in the initial build of
ATOS are then described. These elements
feasibility research for advanced air traffic
management concepts. The Air Traffic include the aircraft components and their future
avionics capabilities, the airborne and ground-
Operations Simulation (ATOS) supports the
based communications, navigation, and
research of future concepts that provide a much
surveillance / air traffic management
greater role for the flight crew in traffic
(CNS/ATM) infrastructure, and future system
management decision-making. ATOS provides
services.
representations of flae future communications,
navigation, and surveillance (CNS)
infrastructure, a future flight deck systems
architecture, and advanced crew interfaces. Bacl_round
ATOS also provides a platform for the The Distributed Air Ground Traffic Management
development of advanced flight guidance and (DAG-TM) concept, proposed by NASA,
decision support systems that may be required describes a set of future traffic operations that
for autonomous operations. redefines the roles of flight crews, air traffic
service providers, and aeronautical operational
control organizations.1 It is based on the premise
Introduction that the sharing of information between these
system participants and the delegation of
The Air Traffic Operations Simulation (ATOS)
decision authority to the most appropriate
is a mid-fidelity simulation under development
decision maker will result in large improvements
to support research of air traffic operations
to airspace system capacity and robustness. 2
within future airspace environments. Hosted by
Distributed decision making authority may also
the Air Traffic Operations Laboratory at the
be a key to enabling large increases in airspace
NASA Langley Research Center, ATOS is a
user efficiency and flexibility, and in minimizing
workstation-based human-in-the-loop simulation
human workload bottlenecks that limit system
that serves as a test bed for investigations of
capacity.
future distributed air/ground traffic management
concepts and their associated decision support
DAG-TM builds upon the concept of
tools. This paper describes the ATOS capability,
"revolutionary evolution" advocated by the
its design, and its application to advanced traffic
Future Air Navigation System (FANS), which
management research. The paper first presents a
cleared the way for a distributed air-, ground-,
brief background of the future concepts under
and space-based CNS/ATM infrastructure.
study and describes the simulation capabilities
DAG-TM also utilizes the idea of user-optimal
routing efficiencies as advanced by the Free
Copyright ©2002bythe American Institute of Aeronautics
andAstronautics, Inc.No copyright isasserted inthe United Flight paradigm, in which airspace users are free
States under Title 17,U.S. Code. The U.S. Government has a to select their path and speed in real-time. To do
royalty-free license toexercise allrights under thecopyright this, advanced airborne systems are needed to
claimed herein forGovernment purposes. All other rights are
enable autonomous airborne flight planning in
reserved bythecopyright owner.
the presence of traffic, terrain, and weather
*Systems Engineer, SeagullTechnology, Member, AIAA hazards. These systems build upon the concepts
tResearch Engineer, NASA Langley Research Center, of Traffic Collision Avoidance System (TCAS),
Associate Fellow-,AIAA Terrain Awareness and Warning System
; Senior Systems Engineer, SAIC, Senior Member, AIAA
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(TAWS), and Windshear/Weathraedrar.
System Flexibility with Variable Fidelity
Througshecurmeulti-layereddatamanagement
The simulation must be flexible enough to
supportebdysystemssuchasActiveDependent
accommodate the different levels of fidelity and
Surveillance-Broad(cAaDstS-B),Controller
different levels of equipage. Workstation
PilotDataLink Communicatio(nCsPDLC),
simulations are usually adequate to simulate
FlightInformatioSnervice(FIS),andTraffic
multi-aircraft scenarios with human operators in
InformationService(TIS), an increased
awareneossf hazardasndconstrainstshould an affordable and manageable way, however,
high-fidelity simulations are occasionally desired
allowcrewsto havegreatearuthorityand
to duplicate a full-crew and full-workload
responsibiliintymanaginthgeirflights.
environment, and to aid in the development of
procedures. The CNS/ATM infrastructure
Thesimulatioonfairspacaendtheoperatioonfs
aircraftwithinit is a usefulandcommon representation must also be flexible to compare
future CNS concepts with today's system. Since
approacfhor thestudyof newair traffic
the future CNS infrastructure will also be
managemenctoncepts,decisionsupport
required to accommodate many legacy systems,
automatioann,dprocedureFs.orinstancteh,e
a range of present and future CNS components
PseudoAircraftSystemwasdevelopetdo
and aircraft equipage levels must be
facilitate the developmentof the
accommodated simultaneously.
Center/TRACONAutomation System)
Additionally, the Federal Aviation
Simulation Repeatability
Administrati(oFnAA)useistsTargeGteneration
Facilitytostudyoperationaailrtrafficcontrol For proper experimental control, the simulation
problem4sw,hichhasrecentlbyeenenhancteod should produce repeatable results. Test subjects
includeahighefridelitydynamicmsode5l.For must be provided with identical situations, so
thestudyoffutureconcepstuschasDAG-TMa, that only test subject actions produce differing
trafficoperationssimulatioisnneedetdostudy results. Additionally, some experiments will test
theinteractionosfdistributehdumandecision algorithms, such as traffic conflict resolution,
makerse,speciallryegardintghetransferof which can produce large response differences to
responsibilibtyetweenairborneandground- small input differences. Simulation repeatability
basedhumanoperatorIst.alsofacilitatetshe for functions such as these is very important for
studyofsupportinsgystemssu, chasdecision the verification and validation of algorithms.
suppotrotolsandfutureCNSinfrastructuaren,d
theirimpactson concepfteasibility. As Modes Of Operation
feasibilityrequirementasnd boundsare The simulation must employ two modes of
establishetdr,afficoperationssimulationis
operation. These are: human in the loop (HITL)
needetodsuppodrtetaileddesiganndevaluation
and human operator modeled batch. HITL is
of air andground-baseddecisionsupport defined as a mode in which subject pilots,
automationc,omputer/huminatnerfacesa,nd subject controllers, and/or subject dispatchers
operationparol cedurWesh.entheseactivitieasre interact with systems or simulators that allow
sufficientmlyaturetr,afficoperationsismulation them to make flight-management or traffic-
canfacilitatteheassessmoefnctoncepbtenefits
management decisions as they would in a
andeconomviciability.
deployed system. Human operator modeled
batch is a mode in which all system operations
Simulation Requirements for Research are simulated with full repeatability, using
automated human operator models to represent
There are 6 main requirements that a simulation
humans in the simulated system.
must meet to be useful as a tool for (CNS/ATM)
research and development:
Component Error Modeling
Success of DAG-TM and other future concepts
Multiple Human Operators hinges upon the quality of information available
to the decision maker. Required Navigation
The simulation must support multiple human
Performance (RNP) compares actual aircraft
operators, each of which is provided a level of
position against required position. Required
sophistication and fidelity that enables them to
Communication Performance (RCP) states
make traffic management decisions as they
would in the actual environment. operational performance in terms of
communication process time, integrity,
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availabilitay,ndcontinuitoyffunctionR.equired
A new version of the simulation is under
SurveillancPeerformanc(ReSP),yetto be
development to provide higher fidelity
defined,will standardizreequiremenftosr
representations of system elements and improved
surveillancaeccuracyP.arametrcicontrolof
utility to researchers and technology developers.
RNP,RCP,andRSPlevelsaswellasthe
Referred to as ATOS Build 1, it resolves several
accuracoyf systempredictioniss needetdo
limitations of the prototype simulation. Among
understatnhdeimpactosftheassociateerdrors
the limitations was the reliance on target
onconcepfetasibilityT.hesimulatiomnustalso
generators for all aircraft other than the test
independengtleynerataendtrackinformation
subject stations. Target generators were
thatrepresenatcstua(ltruth)valuesfromthat
developed to enable many simulated aircraft to
whichrepresenvtasluesavailablteosimulation
be controlled by pilot operators (referred to as
componeanntsdparticipants.
"pseudo-pilots"), who in turn receive voice
clearances and instructions from ground-based
human controllers. However, the aircraft
Simulation Execution Control represented by these simulations normally have
no capability to avoid conflicts, and it is
Simulation execution control is normally used in
impractical to expand their capability. These
flight simulators that utilize a real-time
simulation environment. To be compatible with simulations, while appropriate to support
such simulations, several simulation mode ground-based air traffic control research, do not
control functions must be accommodated. These adequately support DAG-TM research
are: initialize, trim, hold, operate, and reset. requirements for large numbers of aircraft and
their systems that enable autonomous operations.
Simulation Evolution
Design Overview
The development of ATOS, formerly known as
In addition to the identified research
Free Flight Simulation, 5 was initiated after an
investigation of existing traffic management requirements, which focus on the research utility
simulations revealed that none met the above of the simulation, several software design goals
goals. Existing real-time simulations were not were set to facilitate scalability and ease of
maintenance:
flexible enough to model future as well as
current operational environments and they lacked
Maximize simulation scalability, so that
the mode control needed for rigorous and formal
large numbers of aircraft can be
research. Existing batch assessment tools were
simulated without exceeding
not suitable because they do not represent human
computational speed limitations of any
decision-making. They also lack the detailed
flight deck and service provider representations process
Develop a simulation architecture that
required for design of decision support
automation tools. avoids the development and
maintenance of duplicate functions
Include a capability to duplicate and
Initial goals for the simulation also included an
distribute simulation components
aggressive development schedule that would
among several facilities, via dedicated
provide research support as soon as possible.
connections and possibly via the
Toward this goal, a prototype simulation was
internet
developed that made much use of existing
Require few or no changes to flight
capabilities. It allows several workstation-based,
real-time aircraft simulators to interact with each deck decision support technology to
interface with ATOS, Langley high-
other and with target aircraft generated by a
fidelity simulations, and Langley
central airspace simulation. Existing software
research aircraft such as the NASA
codes developed by NASA and National
Airborne Research Integrated
Aerospace Laboratory of the Netherlands (NLR)
were modified to create the initial prototype, a' 7 Experiments System (ARIES), a
which has been used to investigate the use of specially instrumented Boeing 757 that
traffic intent information in constrained air- is used to support in-flight validation
activities.
traffic operations 8.
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ATOSBuild 1 is anextensibldeistributed
generation capability is not compromised. With
systemconsistingof many independent
the addition of a pilot model for each aircraft
processtehsatoperataendcommunicawteith
simulation, background traffic can be
eachotherthroughthenetworkT.heBuild1
represented without the need for pseudo-pilots,
systemcomponenatrseillustrateindFigure1.
or the entire simulation can be executed in a
Thesystemarchitectuisreflexibletoallowfor
batch mode to support Monte-Carlo analysis.
experimentainl vestigationosf competing
systemdsevelopfeodrautonomooupserations.
ASTOR also models a generic future flight deck
architecture that contains air/air and air/ground
f\
datalinks, and advanced crew interfaces, and it
/ \ hosts the flight management systems and
decision support systems required for
Generator (TG) _ Raw]_D_B, pilotcommands Pseudo-P_ilot autonomous operations. These processes are
! _ Inte independent from the aircraft simulation code
-aircrattBackgr°und _ton_/corffrol, i ASTOR states, I (PPI) I
truth windst _?nulation control I I itself, to provide accurate representations of
F,g_, I i !
aircraft equipage. The simultaneous use of
Service (FIS) RawADS-B ! I (pilot, pseudc-pilot, orpilot various versions of ASTOR enables the
-PolIyngfoornmatiowneather _-B Truth aircraft_taties] AutonmoomdoeulscontrolleAdi)rcraft
--WSinds/teDmps alott investigation of operations involving various
-D-ATIS Isimulat_n control [ Data Link Simulator aircraft types with differing equipage levels as
Simulation ISirn_atiion control Ra_ [ Mode SM(DoEdeSl) well as widely varying performance and
UAT Model
Manager (SM) _ I operating characteristics.
-Scenario initialization _ i _1' ADS-B
-Mode control [MonitOr (hear?heat(s), •t-I ASTOR
-Timing control _trors)i truth aircraft F_ISB -Sensor Package
--SiHmeuallathtionMMoonniittoorriinngg _Iate !'i pTsresuthd__s-p'iiot ' --DCiosnptlraoyls Panels
-Truth winds I / cornrOands' -Aircrart Model Simulation Architecture
simulation 'nl_notrol -TM°de'\
Truth Data _ \ / To support such generalized simulations
' wTerastthhewriods, \_2)istributec_ ! involving a large number of independent
\ Networl_ _
Advanced Flight Deck systems, a sophisticated software network is
Decision Support Tooh
required.
Figure 1. Illustration of the distributed system,
which enables flexibility and extensibility
HLA (High Level Architecture)
The ATOS infrastructure is based on the
An independent aircraft simulation, referred to as
the Aircraft Simulation for Traffic Operations Department of Defense's (DoD) High Level
Research (ASTOR), is employed for each Architecture (HLA) 9. The use of HLA to
aircraft represented within ATOS Build 1. These implement the interfaces between the ATOS
workstation-based, HITL aircraft simulations components enables a widely distributed
have 6 degree of freedom dynamic models simulation limited only by the available
hardware resources on the network. Each ATOS
supported by actual aircraft aerodynamic data.
The dynamics model can simulate jet and piston component, known as a Federate in the HLA
aircraft, and the simulation is equipped with paradigm, communicates through the distributed
representative cockpit displays and equipage network, eliminating the need for centralized
levels for the different types of aircraft. control of data flow that has in the past limited
Furthermore, the models are extensible to the extensibility of the simulation. Furthermore,
the use of HLA enables the inclusion of other
different aircraft types by simple
aerodynamic/propulsion parameter changes. simulation assets such as full cockpit simulations
that require remote access.
The aircraft simulations can be executed with
pilot test subjects in HITL operation, or pseudo- Federation Components
pilots can drive them as background traffic. This Each ATOS component is a separate software
form of background traffic is much more capable process that usually operates on hardware
than target generated traffic and can be expected dedicated for that process. These processes
to have the same behavior as the HITL aircraft. include aircraft simulations, airport models, and
If necessary, additional traffic can still be target generators. The simulation manager is a
provided by target generation software for large federate that is used to manage the simulation.
simulations, since the currently existing target The only non-federate is the Run Time
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Infrastructu(RreTI)execa,nHLAproceswshich
particular federate through its real-time scripting
manageHsLAcommunicatioannsdotheHr LA
capability. The scenario and
specifictasks.Figure2 illustratesthe
componeonfttsheFederation.
Commanded Simulation time
mode display display
Buttons for pop-up
SIM MANAGER RTI EXEC windows .........
File name
federates and message traffic entry
monitors federate within the federation Real/Fast
health
Manages _ _ Supports HLA batch control
I I Mode control ..............
Federate mode
1 Standard Netwerk status and health .......
display
I FEDERATE I I FEDERATE 2 FEDERATE n
Simulation
message
display ..........................
Hardware resources for running multiple federates
Figure 2. Illustration of aFederation, the
Termination .................
simulation architecture when using HLA control
RTI Executive and Interactions Figure 3. Detailed explanation of the simulation
The Real Time Interface (RTI) executive, which control window
is part of HLA, monitors the joining of the
federation by federates and manages the various
event window is pictured in Figure 4. The
messages that can be sent within the federation.
scenario manager also has a planview display
Within the HLA paradigm, these messages are
which allows the operator to monitor the airspace
referred to as interactions. The number and types
being modeled.
of interactions are defined at the beginning of the
simulation by the RTI exec and its associated
data files. Each federate subscribes to a subset of
Simulation Modes
the total available interactions when it is
The simulation manager controls transition to
initialized. The federate also agrees to publish
and from various system modes. Figure 5 shows
certain types of interactions. Examples of these
interactions include aircraft state information and the simulation modes and the possible transitions
simulation state modes. The end result is that the between them. The modes include: Configure,
any federate can send or receive information Reset, Trim, Hold, Operate, and Terminate.
to/from any other federate directly.
Configure
The CONFIGURE mode is the mode that the
Simulation Manager federate application enters after being started.
The CONFIGURE mode cannot be transitioned
The simulation manager is the primary
to from any other simulation modes. Configuring
simulation control and monitoring station. The
simulation control window, illustrated in Figure
3, controls the simulation state and monitors the
health status of all the federates during the
simulation. It can command the federates into the
various states such as reset, hold, and operate.
The second window, the scenario and event
window, can record important events, collect
data, and send specialized instructions to a
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Trim
The TRIM mode allows federates to reach a
steady state before running the current scenario.
For aircraft federates, the TRIM mode may
involve determining the control surface
deflections and power settings required to reach
equilibrium. For other federates that do not need
to achieve a steady-state condition, TRIM may
simply be a_'do nothing" mode.
Hold
The HOLD mode is one where the federates
have been initialized and trimmed and is ready to
run the scenario. The HOLD mode also occurs
when an active simulation has been temporarily
suspended. In the HOLD mode, the simulation
clock does not advance, however, user interface
displays are allowed to change
O_Operate
The OPERATE mode is where the federates are
Figure4.IllustratioonftheScenaraiondEvent
window running the simulation scenario.
Sna2shot
consistosf initializingfederateasndallnon-
The SNAPSHOT feature saves the current state
scenarrieolateddata.
of the system to disk so that it can be used as the
starting point of a future scenario. Each
component is required to identify and save its
own mode information needed to meet this
objective.
Terminate
The TERMINATE mode shuts down the
federates. Once the component has exited, it will
need to be re-launched in order to be used again.
Health Monitoring
The simulation manager maintains a record of
the system health. To do this, each federate sends
a periodic message indicating its current state
and its current health status. There are three
Shutdown health statuses: Normal, Warning and Failed.
The federate status is presented to the operator
on the simulation control window in green,
Figure 5. Simulation Modes and Transitions
yellow, or red indicator lights. If a federate
completely fails, and is unable to send any
messages back to the simulation manager, the
Reset
simulation manager flags the federate as failed
The RESET mode applies or reapplies initial and posts a red indication after a specified
conditions. number of missed messages.
Figure 6 illustrates a failure of one of the
federates. In this case, the overall system status
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rowindicateasfailedfederasteomewhewriethin typesashormt essaignedicatintghesignificance
thesimulatioTn.heoperatoisrthenalertetdo oftheevenTt.hisfeatureenablethseresearcher
determinwehichfederahteasfailedbyscrolling toeasilyfindthespodturingdataanalysis.
througthhefederatleist,orbyreadingfailure
messagweisthinthemessabgoex. Federate which will Monitors the success Used toselect the target
receive the script ofthe transmission federate, the federate which
message will receive the command
Monitors whether or notthe Enables the user topage through
federate could execute oldcommands and use them as
the command the basis for new commands
Contains the command
sent tothe federate Sends the command tothe
federate
Figure 7. Illustration of the real time scripting
feature in the scenario and event window
Note Posting
Figure 6. Illustration of the simulation manager The operator can also take notes with a small text
indicating a failure on ASTOR 2 editor that is positioned in the middle of the
Scenario and Event window. These notes are
posted to the data file when they are submitted
and to not pertain to any particular event.
Real Time Scripting
Under certain conditions, the operator may wish Data Collection
to send a specific set of instructions to a federate
Each federate is responsible for collecting its
while the system is running. Examples might
own data. The simulation manager is responsible
include sending a new route to an aircraft
for instructing the federates as to whether data is
simulation federate, or a different data file name
to be collected. The simulation manager collects
to a FIS federate. This task is accomplished
its own data which consists of all messages
using the top portion of the scenario and event
received from the federates, all notes, and posted
window as illustrated in Figure 7. The operator events.
can choose a federate to receive the message
from the federate list. Then a string is typed in
Operating Modes
the message box. When the string is sent to the
appropriate federate, the simulation manager The ATOS software supports an emulated real-
responds with two confirmations. These are: 1. time and a batch mode of operation.
The message was received, and 2. The message
Emulated Real Time
was understood and complied with.
The emulated real-time mode is equivalent to
real-time (or synchronous) operation, except that
Event Marking a real-time operating system is not used. In
The scenario and event marker also enables the emulated real-time mode, a frame overrun is not
an error. Components can attempt to "catch up"
operator to mark interesting or noteworthy
by immediately re-executing the task instead of
events. The operator marks the event and then
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waitingforthenextclocktick.Theemulated
Time Synchronization
real-timeoperatinmgodehastwosub-modes:
The simulation manager controls the master
humanin theloop(HITL),asillustratedin
clock of the simulation and periodically sends
Figure8,andfasttime.InHITLmodet,he
out a time-stamped message to all of the
simulatiotnimealwaysadvanceasta normal
federates. This message is used by the federates
real-timreate,i.e.atthesamerateasawall
to insure they are synchronized with the master
clockT.hefast-timmeodeisimplementaesdthe
clock.
"speed times N function" defined in ARINC
610A 1°.
Aircraft Simulations
While any aircraft simulation that complies with
.........Subject Pilot Pseudo Pil_St_ion
the basic federate infrastructure of ATOS can be
used, the primary aircraft simulation is ASTOR.
ASTOR supports four objectives:
• Advanced mid-fidelity aircraft simulation
with enough sophistication to study DAG-
...... Pseude PilotStation
TM concept feasibility while remaining
simple enough to execute on aworkstation
platform.
• Modular architecture, which facilitates
simulation of various aircraft types, each
with unique airframe/engine and
Figure 8. Illustration of HITL mode consisting
autopilot/autothrottle models, flight deck
of subject pilot workstations with high fidelity
displays/controls, and various avionics
background traffic provided by pseudopilots
equipage levels.
Batch Mode • Advanced avionics modeling
representative of the future CNS/ATM
In batch mode, the executions of periodic tasks environment.
are not synchronized to a clock. Periodic tasks
• Capable of operating in several
run at the fastest rate that the underlying
configurations to support research requiring
hardware and operating system allows, or the
piloted aircraft, pseudo-piloted aircraft, and
clock tick is substituted for an asynchronous
aircraft with modeled pilots (batch mode).
event. Unlike emulated real-time operation,
event-driven tasks may be allowed to run Mid-Fidelity Workstation Based Simulation
without preemption by the periodic tasks. Batch
ASTOR was conceived as an instance of the
mode is illustrated in Figure 9.
Langley Standard Real-Time Simulation
(LaSRS) framework 11. LaSRS has successfully
BatchPilot_t_tion BatchPilotStar!on
been applied to a spectrum of aircraft simulations
ranging from mid-fidelity workstation-based
general aviation simulations to high-fidelity full-
motion cockpit air transport category
B_tchPilotstation :_x_!:_:_._ B_tehPil_=tgtatiOn simulations. As such the flexibility of this
framework is proven.
The DAG-TM concept may rely on advanced
Figure 9. Illustration of batch mode
trajectory management functionality provided by
functionality
the autonomous operations planner (AOP), 12
which continuously provides a conflict free route
While the simulation architecture supports batch to the crew, and real time flight management
and fast time, not all federates may be able to do (FMS) subsystems. The FMS guidance function
this. The use of these tools is dependent on the may need to provide provides continuous closed
nature of the individual federates that comprise loop (temporal and spatial, i.e., 4D) guidance
the simulation. commands to the auto -flight /auto -throttle
systems. ASTOR must host these advanced
functions for each simulated aircraft that is
equipped for autonomous operations.
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properties, propulsion, flight controls, displays,
Matchepderformanaccerostsheaero
/ mass / and avionics have been abstracted from the
propulsion, auto-flight / auto-throttle and
AOP/FMS models is essential for viable DAG- generic six degree of freedom ASTOR
TM research. This need for matched and simulation framework. Models for a large array
appropriate levels of representation for traffic of aircraft types with widely varying
management research in turn drives the need for performance and equipage levels are in
the accurate modeling of climb, cruise, idle- development.
thrust descent, and final approach phases of
flight; dynamic aircraft mass as afunction of fuel Figure 10 through Figure 12 show the ASTOR
bum, which affects climb and descent Flight Deck displays, which are representations
performance; and throttle/thrust lever position, of currently available equipment enhanced for
altitude, and Mach effects on engine dynamics. autonomous operations.
Modular Architecture
To meet the meta-simulation requirements
associated with DAG-TM research and airborne
technology development, all aircraft type-
specific features such as aerodynamic data, mass
N
Figure 10. MD11 ASTOR Pilot Station
Figure 11. Boeing 777 ASTOR Pilot Station
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Figure
12. Lancair C300 ASTOR Pilot Station
The flexible nature of the avionics architecture
Advanced Avionics Modeling enables ASTOR to represent a spectrum of actual
aircraft equipage levels. Fundamental design
The ASTOR design focuses on a modular
components (e.g. GPS, IRS, FCC, TMC, and
avionics architecture which achieves ahigh level
FMS) can be individually selected for a
of functional integration in the spirit of state of
the art integrated modular architectures for particular equipage level. These interfaces
avionics as employed in the commercial Boeing between components are also explicitly modeled
777 and military F22 designs.13 and represent realistic avionics architectures at a
high level. The flexibility of ASTOR enables
researchers to consider/understand/model both
This additional level of fidelity supports a
fundamental research goal to enable ASTOR to legacy systems and industry modernization plans
such as ARINC660A.
not only assist in concept level development, but
also provide insight in to the design of the actual
hardware that would be required in a real flight
deck. Integrated CNS Avionics Architecture
The advanced autonomous flight deck features
ASTOR bridges the gap between system-level embodied in the AOP and FMS subsystems are
design / assessment tools and detailed subsystem integrated into a CNS/ATM avionics architecture
designs, which are needed to support compatible with AR1NC660A. The AR1NC
implementation of future concepts, but often can 660A CNS/ATM standard provides key design
not easily be tested in a distributed environment. guidance for CNS functional partitioning. The
ASTOR provides an appropriate level of AR1NC 429 DITS data bus is simulated for the
modeling in terms of information transfer, and widest range of reverse and folward
information quality (RNP, RCP, RSP). These compatibility.
attributes enable the prototyping of various flight
deck concepts with a level of operational realism Figure 13 illustrates the integration of AOP and
that can address feasibility, robustness, and FMS elements of the Future Autonomous Flight
certification concerns as necessary for the Deck into an AR1NC 660A CNS/ATM avionics
validation of the resultant research data. This architecture.
type of interaction between subsystems is critical
to understanding the detailed flight deck design
requirements.
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