NASA ASAS Activities - ASAS TN by ewghwehws


									   National Aeronautics and Space Administration
   Next Generation Air Transportation System
   Airspace Project

                          NASA ASAS Activities:
                           Decision Support for
            Airborne Trajectory Management & Self-Separation

                                                        Robert A. Vivona
                                                      AOP Lead Engineer
                                                      L-3 Communications
                                                          Billerica, MA

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                        1
           Presentation Overview

• Background
  – Airborne trajectory management

• Autonomous Operations Planner (AOP)
  – Provided ASAS functions
  – System interface
  – Capabilities

• AOP Experimental Performance

• Concluding Remarks
        Background: Airborne Trajectory Management

  Concept                                                                   Terminal Airspace (Merging & Spacing)
  • Trajectory-oriented operations                                                              Q
         –    En route & transition to terminal        En Route Airspace

  •     Aircraft self-optimization
  •     Mixed environment
         –    Self-separating & ground managed

  Self-separating aircraft:
  • Flight-deck decision support                                                                    Self-separating
      equipped                                                                                     Ground managed
         –    Autonomous Operations Planner
  •     “Autonomous Flight Rules”
         –    Self-separate (traffic & area hazards)
         –    Conform to flow constraints
         –    Don’t generate conflicts within 5 mins
  •     Broadcast state & intent data
  •     FMS & air/ground data link equipped                  ATSP Responsibilities
                                                             • Manage airspace resources
  Ground managed aircraft                                        – Generate flow constraints
  • Similar to today’s operations                                – Datalink to autonomous aircraft
  • Broadcast state (and intent) data                        • Control ground managed aircraft

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                                   3
         Autonomous Operations Planner (AOP)
  Purpose: enable trajectory management
  • Conformance to constraints
         –    Separation from traffic aircraft
         –    Avoidance of special use airspace
         –    Minimum penetration of weather hazards
         –    Conformance to time-based flow
              constraints                                  Tactical Maneuver
                                                                                Resolution Maneuver
  •     Path optimization                                  Restriction Region
                                                                                Uploaded to FMS as

  •     Supports navigation & guidance decisions                                    Mod Route

                                                        Area of Conflict
                                                        Along Current
  Concept of use                                          FMS Route

  • Detects & alerts need to modify trajectory
  • Supports trajectory modifications:
         – Strategic & tactical maneuver alternatives
         – “What-if” maneuver analysis                                                      Aircraft
  •     Generates user-optimal paths
  •     Automatically adapts to flight-crew
        chosen guidance mode
                                                                                Navigation Display

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                    4
                    AOP: Provided ASAS Functions
                                ASAS Functions*                                                         AOP Approach
   Traffic Data      Identify Reference Aircraft                               Primary Function: Uses ADS-B and TIS-B information to track
                                                                               and predict traffic aircraft behavior.
                     Track Reference Aircraft
                     Provide Reference Aircraft’s Trajectory
                     Assessing Initiation Criteria                             Not supported (though could be). Not yet required for current
                                                                               research efforts.
                     Assessing Continuation Criteria
                     Assessing Termination Criteria
   Merge             Compute Maneuvers to Merge                                Not required. Separate system (PDS) at Langley provides
                                                                               merging & spacing capability.
                     Compute Merge Location
   Follow            Compute Dependent Following Trajectory
   Manage            Compute Speeds to Achieve and Maintain Interval
                     Monitor Interval Conformance
   Separation        Monitor Maintenance of Separation                         Secondary Function: Uses state-based CD&R for blunder
   Maintenance                                                                 protection.
                     Compute Guidance to Maintain Separation
   Conflict          Probe Trajectory For Conflicts                            Primary Function: Uses both intent-based and state-based
   Detection                                                                   approaches.
                     Alert Crew to Conflicts
   Conflict          Compute Vertical Maneuvers to Provide Separation          Primary Function: Uses both strategic and tactical approaches.
                     Compute Lateral Maneuvers to Provide Separation
                     Compute User-Preferred Trajectory to Provide Separation
   Trajectory        Compute Traffic-Constrained User-Preferred Trajectory     Primary Function: Provided by provisional trajectory analysis.
                     Compute Aircraft Performance
                     Compute Maneuvering Flexibility                           Primary Function: Looks within and outside resolution horizon.
                                                                                     *Source: FAA/Eurocontrol Cooperative R&D AP23
ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                                                             5
                                 AOP: System Interface

 Inputs:                                                                                                  Flight Management
 • Guidance settings                                                                                         System (FMS)
 • Traffic data
 • Weather data
 • AOP MCDU data                                                            Mode Control Panel (MCP)       Flight Control
                                                                                                          Computer (FCC)

                                                                                                          Other Sources:
                                                                                        AOP               • GNSS Clock
                                   AVIONICS DATA BUS

                                                                                       Inputs             • ADS-B
  Autonomous                                                                                              • TIS-B
   Operations                                                                                             • FIS-B
  Planner (AOP)

                                                       Multi-Function Control
 Outputs:                                              & Display Unit (MCDU)
 • Conflict alerts
 • FMS route mods
 • MCP setting mods
 • AOP MCDU data
     Integrates with                                       Outputs
     Existing Avionics
     & Displays
                                                                                     Navigation Display        Primary Flight Display (PFD)
ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                                                           6
                                        AOP: Capabilities

  • Conflict management
         – Probe multiple maneuvers for situation awareness
         – Conflict detection and resolution details
                 • Intent-based and state-based approaches

  • Maneuver without conflict (conflict prevention)
         – Provisional (“what-if”) planning
         – Maneuver restriction bands

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008           7
                                   Conflict Management

  • Approach:
         – Probe all relevant maneuvers (trajectories) requiring evaluation by flight crew
            • Display all conflicts to provide complete situation awareness
         – Provide resolution capabilities for each maneuver

  • AOP can simultaneously predict/evaluate multiple ownship maneuvers
         – Maintaining current guidance (Commanded Prediction)
                         – Evaluate impact of current guidance settings
                         – “What happens if I don’t change the guidance settings?”
         – Reconnecting to strategic route (Planning Prediction)
                         – Advise & evaluate maneuver to re-establish FMS active route
                         – “How do I get back to my long-range plan?”
         – Stop maneuvering (State-vector projection)
                         – Evaluate impact of maintaining current state
                         – “What happens if I stop or don’t start/continue maneuvering?” (e.g., blunder)

  • Not all maneuvers always relevant

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                        8
                                   Conflict Management
                                 FMS Predicted
                                                                  State vector projection
                         VNAV PATH
                                                          VNAV ALT
                                                                              Commanded prediction
                           MCP altitude limit

                                                                                         Planning prediction
                                                                     VNAV PATH
                                                          Active Route
                                                      Altitude Constraint
                     Primary CD Alerting                                          Secondary CD Alerting

      Commanded Prediction                                           Planning Prediction
      • Predicts impact of current guidance                          • Predicts impact of most strategic path
        mode settings                                                       • Predicts VNAV PATH descent
             • Initiates VNAV PATH descent                                  • Ignores MCP altitude
             • Predicts guidance switch to VNAV                      • Secondary CR impacts non-active path
               ALT at MCP altitude
      • Primary CR impacts active guidance                           State vector projection
                                                                     • Predicts impact of not initiating descent
                                                                            •State projection at cruise altitude
                                                                     • Point out / override CD&R
ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                                9
                                   Conflict Management

      • Primary conflicts on the commanded prediction
      • Secondary conflicts on planning and blunder (state-vector)

                    LNAV                                TRACK HOLD           TRACK HOLD

                                                                 Commanded       Commanded


       Last                                           Planning
       LOS      First

                  On path                                   Off path            Off path
                                                         Within capture      Beyond capture

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                           10
                               Conflict Management:
                           Conflict Detection & Resolution

  • Intent-based conflict detection
         – Trajectory prediction
                 • Ownship
                 • Traffic
         – Trajectory prediction uncertainty buffers

  • Intent-based conflict resolution
         – Strategic & tactical

  • State-based CD&R

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008          11
          Conflict Management: Intent-Based CD

  • 1xN probing of ownship versus all hazards (traffic and area)
         – Probes ownship 4D trajectory against all traffic aircraft 4D
           trajectories and area hazard geometries

  • Configurable research parameters                               ownship

         – Required separation zone
                 • Independent values for AFR & IFR traffic
         – Look-ahead
                 • Typically 10 minutes

  • Uses prediction uncertainty bounds
         – Independent definitions for                                       traffic

             • ownship and traffic
             • different maneuvers (flight modes)
         – Conflict = predicted loss between uncertainty regions
ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                    12
          Intent-Based CD: Trajectory Prediction


                                            State Vector Report (SVR)
                                                  Mode Status Report (MSR)
                                                        Air Referenced Velocity Report (ARV)
                                                              Target State Report (TSR)
                                                                   Trajectory Change Report (TCR)

  •     Ownship                                                         •    Traffic
         – Generated from aircraft guidance                                   – Generated from ADS-B data
           settings                                                           – Primarily based on:
         – Primarily based on                                                     • SVR: initial condition
             • Sensors: initial condition                                         • TCR: represents predicted
             • MCP, FMS, FCC, MCDU                                                  trajectory
                settings                                                                   – TCP+N approach
         – Numerical integration using internal                               – No numerical integration
           trajectory predictor                                               – Exploring using TSR with integration
             • FMS quality prediction for all                                   for tactical guidance modes
                guidance modes                                                – One trajectory per traffic aircraft
         – Trajectory generated for CD                                          (used for all CD applications)
           application (commanded, etc.)

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                                    13
                              Intent-Based CD:
                  Trajectory Prediction Uncertainty Buffers



                                                                     •      4D “tube” around 4D trajectory

                                                                     •      Encapsulates prediction
                                                                            uncertainties unique to each
                                                                            segment type

                                                      Lateral path

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                          14
                              Conflict Management:
                         Intent-Based Conflict Resolution
  • Strategic
         – Develops FMS-compatible routes
            • Uploaded directly into the FMS
         – Crew requested (semi-automatic)
         – Solution:
                 • Independent lateral and vertical maneuver options
         – Approach:
                 • Resolves all conflicts and constraints, non-cooperative (priority rule-based)
                 • Pattern-Based Genetic Algorithm
  • Tactical
         – Develops MCP setting advisories
         – Automatic when FMS decoupled or short time to conflict
         – Solution:
                 • Independent altitude, vertical rate, heading/track options
         – Approach:
                 • Resolves all conflicts, non-cooperative (priority rule-based)
                 • Sweep until first conflict free setting found

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                15
                              Conflict Management:
                         Intent-Based Conflict Resolution



                                   Active Route: Magenta
                                   Resolution Route: Blue
                                                                                                    Vertical Rate

                                                                                                     Primary Flight

                                                 Nav Display   Nav Display

         Strategic Intent-Based CR                                           Tactical Intent-Based CR

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                                 16
    Conflict Management: State-Based CD&R
•   Independent system from intent-based CD&R

•   Supports
     – Blunder protection
     – Override for short term conflicts

•   Approach
     – Two options
          • NLR (Modified Voltage Potential)
          • Langley (KB3D)
     – Resolution advisories
          • Independent MCP settings
               – track/heading, vertical rate, altitude
                                                                  Modified Voltage Potential
          • Automatically displayed when needed
     – Similar characteristics
          • Resolves most immediate conflict
               – Cooperative/Non-cooperative (configurable)
          • Maneuver to increase to minimum separation standard
          • Implicitly coordinated with other traffic maneuvers
          • CD
               – Look-ahead at 5 minutes (configurable)
               – No area hazard detection
               – Does not consider uncertainty
                                   Maneuvering Without Conflict
                                      (Conflict Prevention)

  •     Provisional (what-if) planning
         – Non-conflict generated maneuver
            • Probe for conflicts before execution
         – FMS provisional
            • Automatic probe of FMS MOD              Manual MOD                        FMS
              route                                   Route in FMS                    Conflict
         – MCP provisional
            • Automatic probe of non-active MCP

  •     Maneuver restriction (MR) bands
         – Protect against unallowable maneuvers
             • Conflicts generated within 5 mins
         – Bands show unallowable MCP settings
             • Lateral (track/heading)
                                                                        Lateral MR
             • Vertical (vertical rate)                 Non-active         Band
                                                      Change in MCP
         – Automatically generated for:                Track Setting
             • Non-active MCP setting change          (e.g., in LNAV)                   MCP
             • Switch to tactical guidance mode                                       Conflict

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                18
                    AOP Experimental Performance
                   Experiment 1: Lateral Only, Random Routes, All Autonomous
                    10X playback speed

                                                               Sustained    Sim.     Simulated    Traffic    LOS2
                                                                 Mean      Hours       flights   conflicts

                                                        2x 3    3.45         36        881         195        0
                                                                 6.11        36       1527         550        0
                                                                8.61         36       2195        1018        0
                                                                11.64        36       3000        1788        0
                                                                15.24        12       1302         963        0
                                                        10x     17.18        12       1560        1256        0
                                                               Totals       168      10,465       5770        0

  NASA Air Traffic Operations Lab                                                      Lateral Strategic CR Only
  All aircraft co-altitude, circle diameter 160 NM
  Sustained Mean Density1 17.18

  1   Aircraft per 10,000 NM2
  2   Loss of separation (5 NM)                                                      Consiglio, Hoadley, Wing, Baxley:
  3   Ref. sector ZOA31 – median density, 19 Feb 2004                      Safety Performance of Airborne Separation -
                                                                        Preliminary Baseline Testing. AIAA-2007-7739.
ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                                  19
                    AOP Experimental Performance

         Experiment 2: Lateral Only, Random Routes, All Autonomous, Pilot Delay

                                  Average         Average       Flight    Total           Total
                                 Density(*)         Pilot       Hours    Conflicts       LOS(**)
                                                      3.5       240.73      583             0
                                                      3.5       90.71       316             1
                                                      3.5       572.76     2307             2

                                           Totals:              904.20     3206             3

                                                                                           Lateral Strategic CR Only
                                                                                                   (CPA < 0.02 nmi)
    (*)Relative to mean and peak 1X densities of 1.8 and 3
    aircraft, normalized to 10000 nmi2, at the most populated
    flight level of the median-density sector on 19 Feb 2004.
    (**) All 3 LOS events were from high-complexity multi-
    aircraft conflicts. The 2 LOS events at the 21.4 density
    involved a 4-aircraft conflict in which one aircraft lost
    separation with two of the intruders.                                                 Consiglio, Hoadley, Wing, Baxley, Allen:
                                                                           Impact of Pilot Delay and Non-Responsiveness on the
                                                                         Safety Performance of Airborne Separation. ATIO 2008.
ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                                              20
          AOP Performance: Batch Experiment 2

         Experiment 2: Lateral Only, Random Routes, All Autonomous, Pilot Delay
                  Number of Conflicting Pairs of Aircraft in Resolution
                                 PM delay of 240 sec, 10sev std dev



          Count     200                                                            As traffic density increases, so
                    150                                                            does the number of multi-

                                                                                   aircraft conflicts, which reflects
                            1         2          3          4         5      6
                                                                                   increased traffic complexity
                    11.2   140       28          3          1         0      0
                    16.3   210       79         11          1         0      0
                    21.4   350       136        46         10         2      0
                                        aircraft per conflict Pairs
                     Number of intruder Number of Conflicting resolutions.

                                                     AOP Intent-Based CD&R Studied
                                                     Under Highly Complex Traffic Scenarios

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                                     21
            Concluding Remarks: Current NASA Efforts

  • SPAS (Safety Performance of Airborne Separation)
         – PI: María Consiglio
         – Studying effects of major error sources (e.g., wind error) on safety

  • SPCASO (Safety & Performance Characterization of Airborne Self-
    Separation Operations)
         – Prediction uncertainty
            • PI: Danette Allen
            • Studying use of trajectory prediction uncertainty bounds to mitigate
              prediction error
         – Mixed operations
            • PI: David Wing
            • Studying impact of mixed AFR and IFR traffic
            • Investigating approaches to mitigating traffic complexity using AOP

  • ADS-B Performance
         – PI: Will Johnson
         – Studying impacts of ADS-B range, interference and limited intent
ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                  22
          Concluding Remarks: AOP References
  •     System Concept
         –    Ballin, M.G., Sharma, V., Vivona, R.A., Johnson, E.J., and Ramiscal, E.: “A Flight Deck Decision
              Support Tool for Autonomous Airborne Operations,” AIAA Guidance, Navigation, and Control
              Conference, AIAA-2002-4554, August 2002.

  •     CD&R
         –    Vivona, R., Karr, D., and Roscoe, D., “Pattern-Based Genetic Algorithm for Airborne Conflict
              Resolution”, AIAA Guidance, Navigation and Control Conference, AIAA-2006-6060, August 2006.
         –    Karr, D., and Vivona, R., “Conflict Detection Using Variable Four-Dimensional Uncertainty Bounds
              to Control Missed Alerts,” AIAA Guidance, Navigation and Control Conference, AIAA-2006-6057,
              August 2006.
         –    Mondoloni, S., Ballin, M., and Palmer, M.: “Airborne Conflict Resolution for Flow-Restricted
              Transition Airspace,” 3rd AIAA Aviation Technology, Integration and Operations (ATIO) Conference,
              AIAA-2003-6725, November 2003.

  •     Experiments
         –    Consiglio, M., Hoadley, S., Wing, D., and Baxley, B., “Safety Performance of Airborne Separation:
              Preliminary Baseline Testing,” 7th AIAA Aviation Technology, Integration and Operations (ATIO)
              Conference, AIAA-2007-7739, September 2007.
         –    Consiglio, M., Hoadley, S., Wing, D., Baxley, B., and Allen, D., “Impact of Pilot Delay and Non-
              Responsiveness on the Safety Performance of Airborne Separation,” 8th AIAA Aviation
              Technology, Integration and Operations (ATIO) Conference, AIAA-2008-8882, September 2008.

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                                                               23

  • Demo
         – ~10x traffic
         – 10x playback
         – Long range
         – No display

      Lateral Intent-Based CR

ASAS TN2.5 Workshop, Rome, Italy, November 13, 2008                      24

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