The Flight Trajectory: AnAirborne Perspective with ATM in mind Miguel Vilaplana Boeing Research & Technology Europe COURSE 102: RESEARCH IN DECISION SUPPORT SYSTEMS FOR FUTURE AIR TRAFFIC MANAGEMENT La Granja 9th -12th July, 2012 www.hala-sesar.net
Contents Introduction ATM transformation, SESAR and Trajectories The Flight Management System (FMS) History Architecture and main functions FMS trajectory ATM-related FMS functions Air-ground interoperability Integration of the FMS trajectory in the ATM system Examples 10/07/2012 2
CNS/ATM Evolution: air and ground technologies Altimeter, Artificial horizon, NDB, first VORs Performance and RNAV Systems First generation FMS, integrated multi-sensor navigation Advanced FMS, GNSS Navigation, RNP, Data Link 65 years 1947 1960 1985 2012 Introduction of primary radar in civilian ATC Secondary Surveillance Radar (SSR) SSR-based ATC and automatic flight data processing SSR-based ATC (Mode S), limited ADS-B and data link communications 10/07/2012 3
CNS/ATM Evolution: Why so slow? First powered flight 1903 First supersonic flight Boeing 707 1947 First moon landing 1958 1969 65 years First ever mobile phone call 1947 Ericsson automated mobile phone (single cell) 1960 Handheld Motorola DynaTac (analogue, $4000) 1983 iphone 4S 2011 10/07/2012 4
Barriers to Change in ATM Procedural inertia Introduction of new technology needs to be accompanied by demonstrably safe associated procedures/practices Human-machine interaction (human acceptance) If it s been safe so far, why change it? Economical factors Potential benefits of technology are hard to assess Multiple heterogeneous stakeholders: who is getting the benefits? Political factors Fragmentation (e.g. national agendas) Complex division of functions/responsibilities 10/07/2012 5
System inefficiencies Drivers for Change: The European Case Forecast traffic growth Environmental Impact: ETS, contrail formation, noise, etc Raising fuel costs 10/07/2012 6
The European Approach to ATM Transformation SES (Single European Sky) Legislation Performance-based ATM system: Targets in safety, environment, capacity, and cost-efficiency Enforced by incentives, charging scheme, possibly corrective actions (penalties) Pillars to implement SES Technology (SESAR) Safety (EASA) Airspace Management (FABs-Functional Airspace Blocks) Network Management (ATFM-Eurocontrol) Airports (and intermodality) Social dialogue 10/07/2012 7
SESAR: From this CNGSA Today Communications: -Voice (VHF/HF/Satellite) -Data-link (not widespread) AIRCRAFT Surveillance: -Radar (PSR/SSR) -ADS-B, ADS-C (not widespread) -Multilateration (not widespread) Navigation and Guidance: -Multi sensor (VOR/DME, GPS, Baro, Inertial) integrated with inertial -Lateral RNP (Required Navigation Performance) -Cost-index based flight plan optimization and automatic 3D guidance (limited timebased guidance) Communications: -Voice (VHF/HF/Satellite) -Data-link (ACARS) ATM SERVICES Automation: -Surveillance/Flight plan processing AIRLINE OPERATIONS CENTER Automation: 10/07/2012 8 -Limited decision support Communications: -Flight Plan filing (limited data) -Basic collaborative decision making -Flight Planning/crew scheduling -Limited in-flight decision-support
to this CNGSAI Tomorrow? Surveillance: -ADS-B in (ASAS applications) AIRCRAFT Navigation and Guidance: -Full RNP (4D, lateral, vertical and time) -Advanced trajectory optimization -Guidance for ASAS applications Surveillance: -Monopulse SSR -ADS-B, ADS-C -Multilateration SWIM Communications: -Enhanced data-link applications -Integration in SWIM ATM SERVICES Automation: -Advanced trajectory-based decision-support tools: AMAN, DMAN, CD&R, etc AIRLINE OPERATIONS CENTER 10/07/2012 9 -Enhanced interoperability Information Management: -Collaborative trajectory management -Information services: weather, AIS, etc Automation: -Advanced dynamic flight/network planning -In-flight decision-support
Trajectories in SESAR Business Trajectory The Business Trajectory represents the airspace user s intention with respect to a given flight. Business Trajectories will be expressed in all 4 dimensions (position and time) and flown with much higher precision than today (very similar to NextGen s definition of 4D trajectory ) Trajectory Management Collaborative process by which the Business Trajectory of the aircraft is established, agreed, updated and revised with participation from all involved stakeholders AOC, aircraft, ATM services (ATFM, ATC, etc) Different possible mechanisms are envisaged to implement dynamic revisions of the Business Trajectory: Constraints (including time) 2D or 3D Precision Trajectory Clearances 4D contracts (clearances that prescribes the containment of the Business Trajectory in all 4 dimensions for the period of the contract) 10/07/2012 10
Definitions of Trajectory Depends on whom you ask and when you ask For example, if you ask EUROCONTROL: A 4D Trajectory is a description of the predicted evolution of the aircraft motion including 3-dimensional geometry and time. A 4D Trajectory is not the guidance objective of the aircraft, but the result of predicting the trajectory that results from flying certain guidance objectives in the presence of a wind and temperature forecast. A 4D Trajectory is given by a 3-dimensional geometry and one or more RTAs to which the aircraft must adhere to. A 4D Trajectory captures geometrical and time guidance objectives of the aircraft. A 4D Trajectory is given by a containment 4-dimenstional tube within which the aircraft will remain for a given look ahead time. A 4D Trajectory expresses 4-dimensional guidance requirements for the aircraft. And you can find elements of all of these definitions in SESAR 10/07/2012 11
A Definition for Today Description of the predicted evolution of the motion state of the aircraft s center of gravity, including 3-dimensional position, velocity (airspeed and ground speed) and instantaneous aircraft mass (and possibly other state variables) The trajectory is the expected result of flying a specific planned guidance strategy in in the presence of a specific wind and temperature forecast The trajectory is typically given by a time-stamped sequence of state samples The trajectory can be a nominal one (deterministic) or may include uncertainty bounds around specific variables (probabilistic) Information on the requirements on the trajectory (RNP, RTAs, etc) or on the guidance strategy may also be available 10/07/2012 12
Flight Planning Pilot and ACARS ( AOC data link) inputs Navigation Database Generation of the lateral profile Performance Management (Trajectory Generation) Performance Optimization Generate full flight vertical and speed profiles consistent with performance modes, operating limits, input flight plan and ATC constraints Built on top of lateral profile (decoupled) Vertical and speed profiles that minimize cost function (Cost Index) or fulfill other criteria Accurate aero and engine models Performance Prediction FMS Primer: Basic Functions (I) Trajectory prediction based on designed profiles and meteo forecast 10/07/2012 13 Generation of guidance targets for Guidance Function
Navigation Determination of best estimate of position and velocity using all available sensors: Inertial, Air data, GNSS, VOR/DME, etc Guidance Lateral Waypoints, legs (roll control) Vertical (speed/thrust) Targets generated from Performance Management (elevator/throttle) Inputs/Outputs Autopilot/Autothrottle CDU (Control and Display Unit) EFIS (Electronic Flight Instrument System) Data Link Communications FMS Primer: Basic Functions (II) 10/07/2012 14
FMS Primer: Basic Arquitecture (1) Flight Management Computer System (FMCS) Two main physical modules: Flight Management Computer (FMC) + Control and Display Unit (CDU) Dual configuration (redundancy) Flight Management t System (FMS) FMCS interfaces with several airborne systems to provide full functionality: Navigation sensors Autopilot system Autothrottle system EFIS Data link communications 10/07/2012 15
FMS Primer: Basic Arquitecture (2) CDU Pilot input (flight plan, objectives, etc) Navigation Database Operational context data FMC FMCS FMS EFIS Predicted trajectory information Trajectory Generation (lateral and vertical) Constraints, Clearances, objectives (AOC, ATC) Data link Communications Autopilot/ Autothrottle Guidance targets Guidance Aircraft state (position, velocity, time, etc) Aircraft state (position, velocity, time, etc) Navigation Sensor data (Inertial, Sensors 10/07/2012 VOR/DME, 16 GNSS, etc)
History of the FMS: The vision Automated Flight Management (AFM) of Future High- Performance Aircraft, Boeing, 1967 10/07/2012 17
History of the FMS: From vision to reality In 1978, Sperry (later acquired by Honeywell) started the development of the first ever FMS for the Boeing 767 (and 757) Merged RNAV System and Performance Management System In 1979, Sperry started the development of the FMS for the Airbus A310 The Brown and Grey families were born First commercial FMS flight: United Airlines B767, September 8, 1982 The FMS was introduced in the Boeing 737 in 1984 (developed by Smiths Industries, later acquired by General Electric) In 1988 the first Airbus A320 is delivered to Air France equipped with a Thales-Smiths FMS 10/07/2012 18
1 ST Generation (80 s) B767, A310, MD-11, B737, B747-400, A320 16 bit processor and hard disk Improvements to first models: Solid state memory and cached RAM Increased database capacity Increased functionality Improved meteo models Multiple step climbs 2 nd Generation (90 s) B777, A330/340, B737NG New avionics architectures (Integrated Modular Avionics) Increased functionality RTA (en route) Data link ADS-C, CPDLC (FANS), enhanced ACARS Introduction of GPS Precision approaches (ILS, MLS) 3 rd Generation (2000 s) B737NG, A380, B787 Enhanced networking Increased functionality History of the FMS: Evolution Multiple RTA, RTA to runway threshold Enhanced trajectory generation and guidance 10/07/2012 RNP 19
Trajectory Generation Atmosphere Flight Intent Trajectory Generation Guidance and Control Trajectory Flight Plan, Cost Index, constraints, etc Aircraft State Aircraft Intent 1 st DOF e.g. 2D Path (Roll) 2 nd DOF e.g. Altitude (Pitch) 3 rd DOF e.g. Speed (Thrust) Control Surfaces Deflections and Throttle : 1 st DOF Roll control (no sideslip) (ailerons + rudder) 2 nd DOF Pitch control (elevators) 3 rd DOF Thrust control (throttle) 10/07/2012 20
Trajectory Generation Model Intent Generation Infrastructure Trajectory Computation Infrastructure Flight Intent Initial Conditions User Preferences Model Operational Context Model Aircraft Intent Initial Conditions Aircraft Performance Model Meteo Model Predicted Trajectory Position, velocity, mass (from Navigation Function) Route, Constraints, Clearances, objectives (AOC, ATC) Cost Indexrelated information (tables) Nav Database Guidance targets (to Guidance Function) Position, velocity, mass (from Navigation Function) Aero and Engine models (tables) Sensed wind and temperature (from Navigation Function) and wind and temperature forecasts Planned/Predicted trajectory (to EFIS, data link) 10/07/2012 21
ATM-related Functions: Cost Index Generate trajectories that result in the optimization of a cost function Time-related costs: Hourly maintenance, flight crew and cabin crew costs per flight hour, depreciation costs, etc Minimize where and Constrained optimal control problem Determines optimum altitude, cruise Mach and climb and descent profiles Pre-calculated and tabulated: three separate problems given a lateral profile ECON Cruise Mach=f(Weight, Temperature, Pressure, Altitude, Wind, CI) ECON CAS/Mach Climb=f(Weight,, Temperature (current and forecast), Pressure (current and forecast ), CI) ECON CAS/Mach Climb=f(Weight,, Temperature (current and forecast), Pressure (current and forecast ), CI) 10/07/2012 22
ATM-related Functions: Cost Index Examples 10/07/2012 23
ATM-related Functions: RNAV/RNP Procedures can be developed without overflight of navigation aids Parallel RNAV routes to improve flow and capacity Reduced miles flown, reduced emissions and improved operating efficiency RNP as an enabler to improved access and traffic flow RNP as an enhancement to operational safety Performance integrity, monitoring and alerting BIF WER THE MAN 10/07/2012 24
ATM-related Functions: RTA A Required Time of Arrival (RTA) is a time at which an aircraft is expected to arrive at a certain fix. Some aircraft, en route RTA only, others into the arrival procedure RTA control is typically implemented through trajectory generation (outer loop) Iterative CI manipulation to re-define Cruise Mach and descent speeds RTA can bring improvements to traffic flow and traffic management 2 min Activate Late Control Entered RTA Time Late RTA Control Early RTA Control +Tol. Tol-3 sec 3-Tol sec -Tol. WER THE BIF MAN -2 min Activate Early Cntrl 2 hours 60xT 3 min Time to RTA Waypoint, T (sec) RTA Windows 10/07/2012 25
ATM-related Functions: Data Link AOC Data Link ACARS and its evolutions ATS Data Link FANS 1/A (Mainly Oceanic operations) ADS-C (include FMS trajectory information) and CPDLC Link 2000+ (Europe data link mandate ATN VDL Mode 2) CPDLC SESAR: RTCA CS214/EUROCAE WG 78 Extended CPDLC, ADS-C EPP (include detailed FMS trajectory information), ETA min/max (i4d) 10/07/2012 26
Potential Issues: Vertical and Temporal RNP? Lateral trajectories can exist end to end, but vertically there are some parts of the flight profile where a defined path does not exist No fixed trajectory The trajectory will vary depending on level/mode of aircraft performance You Get This, Not That Trajectory Profile View 10/07/2012 27
Potential Issues: Aircraft equipage Requirements on new airborne equipment and functionalities Business case for airlines Mandates? Retrofit/forwardfit 10/07/2012 28
Potential Issues: Air-ground Interoperability Trajectory Information Models Content and format Enable a common, synchronized view of the trajectory Considering requirements of airborne and ground-based systems (including legacy) Trajectory Information Management How does the ground design amendments to Business Trajectories Trajectory prediction for constraint design Trajectory Management Services offered by SWIM Protocols for multi-party trajectory negotiation Roles and responsibilities, access, security 10/07/2012 29
Potential Issues: FMS trajectory GROUNDSPEED FF ETA error [s] WINDS TOD ETA error [s] Actual Trajectory 10/07/2012 30
Air-ground Integration examples: i4d 10/07/2012 31
Air-ground Integration examples: ASIS Study synchronization of predicted trajectories between FMS and ground TPs (current generation, operational systems) Comparison between predictions performed with and without considering aircraft intent information obtained from the FMS Use reference trajectories of actual flights, untouched by ATC (User- Preferred Trajectory/Business Trajectory) Thanks to Airservices Australia and Qantas 2 Flights Sydney-Melbourne (QFA417 and QFA401) 1 Flight Sydney-Adelaide (QFA735) Assume everything synchronized except for aircraft intent: Focus on synchronization with FMS prediction with zero wind and known atmosphere 10/07/2012 32
Air-ground Integration examples: ASIS AIDL: Aircraft Intent Description Language Flight Plan Snap AIDL Translator *. t x t *. x m l AIDL to Indra TP Translator AIDL to Barco TP Translator Flight Management Workstation w / sfms Indra TP Barco TP 10/07/2012 33
10/07/2012 34
10/07/2012 35
10/07/2012 36
10/07/2012 37
QFA 417 I-NAI I-AI B-NAI B-AI Time (s) 57.131 23.768 14.19 14.007 Alt. (ft) 2314.3 620.66 2087.4 1290.2 CAS (kts) 13.383 6.8442 19.779 5.9701 Lat. dev(nm) 1.7651 0.074845 0.44941 0.1649 QFA 401 I-NAI I-AI B-NAI B-AI Time (s) 40.959 29.94 77.936 21.527 Alt. (ft) 549.55 511.12 1753.5 1271.6 CAS (kts) 9.9397 6.4624 15.868 6.7401 Lat. dev(nm) 0.38633 0.062826 2.5075 0.17346 QFA 735 I-NAI I-AI B-NAI B-AI Time (s) 104.82 100.34 68.354 19.273 Alt. (ft) 1022.8 807.66 4147.7 1017.2 CAS (kts) 12.419 6.9512 28.03 6.2129 Lat. dev(nm) 0.79271 0.21319 2.7467 0.22816 10/07/2012 38
Air-ground Integration examples: ASIS 10/07/2012 39