Traffic Manager (TMX) Modifications to
Support NextGen Studies at NASA-Langley
Research Center
Kurt W. Neitzke
NASA Langley Research Center
Innovations in NAS-Wide Simulation
George Mason University, VA
27-28 January 2010
National Aeronautics and Space Administration GMU-SIM-JCS, January 2010 1

Outline
I.
TMX Background & Overview
A. Development History
B. Architecture
C. Supported Research Studies
II. Current enhancements
III. Remaining Gaps
National Aeronautics and Space Administration GMU-SIM-JCS, January 2010 2

Background **
• TMX development began in 1996 by National Aerospace
Laboratory of the Netherlands (NLR) to study “Free Flight” , where:
– Properly equipped aircraft allowed to choose own flight path
– While maintaining separation from all other aircraft (airborne separation assistance system (ASAS))
• Originally designed to support human in the loop (HITL) studies related to Free Flight to develop and compare different conflict resolution algorithms
• TMX updated periodically to date, by NASA Langley and NLR to support specific research studies primarily related to airborne separation assistance
• Evolved capabilities now include:
– Stand alone Fast-time or Batch simulator
– Links readily to other air traffic simulations (e.g. Airspace and Traffic
Operations Simulation (ATOS) at NASA-LaRC)
** Source: Traffic Manager: A Flexible Desktop simulation Tool Enabling Future ATM Research;
Bussink, F.J.L., et. al., 2005 IEEE
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TMX Overview
TMX features Include:
•
Operates on single computer platform, Windows OS
•
Capable of ~ 2000 aircraft simultaneously aloft (typ. supporting regional, not NAS-wide studies)
•
BADA performance models (200 aircraft reference fleet)
• Autopilot model (with basic altitude, speed and heading modes as well as the FMS coupled LNAV (lateral) and VNAV (vertical & speed) modes
• Conflict detection & resolution (CD&R) system selectable from up to 10 variants or none, including state, and intent based
• Conflict Prevention System (P-ASAS) – “Go – No-Go” bands on cockpit display to prevent pilot maneuvering into short-term (< 5 min. typically) conflicts
• A 4D-FMS with route following, & Required Time of Arrival (RTA) meeting (closed loop) capability
•
Pilot model with parameters for reaction time, scheduling effects and recovery manoeuvres
•
ADS-B models
– Separate transmit & receive models
– Includes range limits & signal drop-out (simple)
•
Winds (truth & forecast)
• Surveillance view or pilot viewpoint GUI (can disable for batch sim’s)
Source: Traffic Manager User’s Manual, Version 5.31; Hoekstra, J.
National Aeronautics and Space Administration GMU-SIM-JCS, January 2010 4

Source: Traffic Manager: A Flexible Desktop simulation Tool Enabling Future ATM Research;
Bussink, F.J.L., et. al., 2005 IEEE
National Aeronautics and Space Administration GMU-SIM-JCS, January 2010 5

TMX Surveillance View
Source: Traffic Manager User’s Manual, Version 5.31; Hoekstra, J.
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TMX Surveillance View
AFR aircraft (green) and IFR aircraft (blue)
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• 2008; A Performance Assessment of a Tactical Airborne Separation
Assistance System Using Realistic, Complex Traffic; Smith, J.C. et. al.,,
The 26th Congress of International Council of the Aeronautical
Sciences (ICAS)
• 2004; Fast-time study of Airborne Merging and Spacing for Terminal
Arrivals (AMSTAR)
• 2004; HITL experiment supporting integrated air/ground operations feasibility under the En Route Free Maneuvering component of
Distributed Air/Ground - Traffic Management (DAG-TM) Concept
• 2004; In-Flight Traffic Simulation for Self-Separation and Sequencing
(SSS) Flight Experiment conducted by NASA LaRC as part of the Small
Aircraft Transportation System (SATS) project
– traffic generation, conflict detection and prevention, visual and audio alerts and was used as a decision support tool in support of self-separation operations
• Integral part of Air Traffic Operations Laboratory (ATOL) at NASA-LaRC
– Interactive background air traffic
National Aeronautics and Space Administration GMU-SIM-JCS, January 2010 8

• Integration of Airborne Coordinated Conflict Resolution and Detection (ACCoRD) based CP-Bands
• Integration of Strategic, Intent-based CD&R capability
StratWay (Strategic Waypoint adjustment program)
• Integration of NASA TFM functionality
• Outline approach for future integration of weather data into TMX
• Create a distributed architecture version of TMX to enable NAS-Wide simulation and higher traffic volumes
(compared with stand-alone TMX)
National Aeronautics and Space Administration GMU-SIM-JCS, January 2010 9

Heading
Band
(degrees)
TMX Conflict Prevention System
Indicated
Airspeed
Band (kts)
Vertical Rate
Band
(100's ft per
Minute)
GMU-SIM-JCS, January 2010 10 National Aeronautics and Space Administration

Integration of Airborne Coordinated Conflict Resolution and Detection (ACCoRD) based CP-Bands
• Conflict Prevention System displays “bands” to pilot to indicate trajectory changes that will cause a short-term conflict (yellow ~ 3-5 minutes; red~ <3 min.)
• CP Bands on:
ˉ Heading changes
ˉ Vertical speed changes
ˉ Horizontal speed changes
• Trajectory changes may be due to conflict resolution or part of the flight plan
• Can be used by pilot model (in batch study, or as background traffic in HITL experiment) or directly by human pilot in HITL experiment
• Includes formal methods proof of “correctness” of the
CP-Bands algorithms
• Replaces existing CP-Bands developed by NLR
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Integration of Airborne Coordinated Conflict Resolution and Detection (ACCoRD) based CP-Bands
• Conflict Bands algorithm uses ACCoRD to determine conflict envelope
•Supports multiple conflict regions
•Deterministic, formal
V&V
Heading conflict zone corrected with altitude and time
Resolution with multiple simultaneous conflicts
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Integration of Strategic, Intent-based CD&R capability StratWay (Strategic Waypoint adjustment program)
• Strategic CD&R algorithm under development is
“StratWay” (Strategic
Waypoint adjustment program)
• Performs piece-wise inspection of planned waypoints
• Uses Bands algorithms for conflict detection and resolution options
• Moves minimum number of waypoints to de-conflict
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• Concept to manage air traffic flow under uncertainty in airspace capacity and demand
• Sequential optimization method
• Integrates deterministic integer programming model for assigning delays to aircraft under en route capacity constraints
• Reactively accounts for system uncertainties
• Assigns only departure controls
• Two additional elements associated with the ref. TFM
Capability related to tactical weather re-routing, and airborne holding will not be integrated into TMX at this time
** Source: Sequential Traffic Flow Optimization with Tactical Flight Control Heuristics; Grabbe,
Shon, et. al., 2008, AIAA Guidance Navigation and Control Conference and Exhibit
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Not included in current TMX mod’s
Source: Sequential Traffic Flow Optimization with Tactical Flight Control
Heuristics; Grabbe, Shon, et. al., 2008, AIAA Guidance Navigation and
Control Conference and Exhibit
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• Purpose: allow the evaluation of different strategic weather mitigation approaches using TMX
• Current, simple TMX weather avoidance capability uses
CP-Bands to tactically avoid 3-D weather poly-spaces
• New Weather databases available soon via NRA;
Realistic Weather Data to Support NextGen ATM
Concept Simulations (two NRA awards: Sensis, &
Raytheon)
– provide recorded real-world and simulated weather data
– Provide associated software tools to manage the data and create appropriate scenarios
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Distributed TMX Nodes
TMX Node TMX Node
Traffic data
TMX Node
ADS-B
CD&R
Scheduling
Time Synchronization
Output Recording
TMX Node
Time Sync.
Resolutions
Central Control Node
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• Capability to handle NAS-wide simulation
• 20,000+ aircraft simultaneously aloft
• Handle full range of mixed AFR-IFR aircraft
• Improve code efficiency
• Shorten simulation run-time
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• Start/stop TMX nodes
• Receive TRAFFIC data
• Traffic range computations
• ADS-B updates
• Conflict detection checks
• Conflict resolution computations
• Send resolutions to TMX nodes
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• Two A/C case TMX vs. 1-node D-TMX
• 1000 A/C case TMX vs. 1-node D-TMX
• 1000 A/C case TMX vs. multi-node D-TMX
(250 A/C per TMX node)
• Detailed (1000 A/C) case checking trajectories and resolutions
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• NAS-Wide simulation tools have matured greatly over the past five years – however:
–
They span a broad system - The NAS! (can the World be far behind?)
– Determining a “prudent mix” of which NAS systems will be explicitly vs. implicitly modeled to deliver the desired information is study-dependent often
– Understanding the validity bounds of results is difficult, and typically “in the eye of the beholder”
• Don’t know whether current simulation capabilities are sufficient to answer highest priority NextGen research questions right now or not
• Need to enter vigorous period of exercising the tools to reveal their capability shortcomings
– Use multiple tools to simulate the same scenario and compare results
–
Synthesize comparison to formulate future tools & methods development plan
• How can broader, lower detail simulations (like NAS-wide) be more directly complementary to narrower, more detailed simulations (and vice versa?)
–
Do NAS-Wide Simulations need to
– “do it all”?
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