Real-Time Trajectory Predictor Calibration through Extended Projected Profile (EPP) Down-Link FAA/EUROCONTROL ATM R&D Seminar Lisbon, Portugal, June 2015 Jesper Bronsvoort & Greg McDonald Airservices Australia Mike Paglione & Christina M. Young FAA Jean Boucquey EUROCONTROL Eduardo Gallo Boeing Research & Technology Europe Joachim Hochwarth GE Aviation Systems LLC
Overview 1. Trajectory Synchronisation 2. Data-Link Standards 3. Aircraft Intent Generation based on EPP 4. Test Scenario 5. Real-time Calibration based on EPP 6. Conclusion
Trajectory Synchronisation Flight Management System (FMS) and ground-based Decision Support Tools all have own version of the trajectory to be flown. The objective of air-ground trajectory synchronisation is to produce trajectories in these disparate systems, increasing the likelihood of flying the planned conflict-free and business preferred trajectories 1. 1 KLOOSTER, J., TORRES, S., CASTILLO-EFFEN, M., SUBBU, R., KANMER, L., CHAN, D., & TOMLINSON, T. (2010). TRAJECTORY SYNCHRONIZATION AND NEGOTIATION IN TRAJECTORY BASED OPERATIONS. PROCEEDINGS OF THE 29TH DIGITAL AVIONICS SYSTEMS CONFERENCE, SALT LAKE CITY, UT.
Data-Link Standards Data-link to synchronise trajectory information essential to TBO Currently (limited) trajectory information can be obtained by ATC from FMS via FANS-1/A as ADS-C Intermediate Projected Intent (IPI) Recently the Extended Predicted Profile (EPP) trajectory down-link standard was created by RTCA and EUROCAE to support air-ground trajectory synchronisation (DO-350/ED-228). EPP extends and improves IPI. Aircraft Communications Addressing and Reporting System (ACARS) Future Air Navigation Systems 1/A CPDLC & RNAV & ADS-C (IPI) Aeronautical Telecommunications Network (ATN) Link 2000+ CPDLC ADS-C EPP 1980 1990 2000 2010 2020
IPI-EPP Comparison General TCP Estimated State TCP Specification Turn Geometry Item Intermediate Projected Intent (IPI) Extended Predicted Profile (EPP) Maximum number of trajectory 10 128 change points (TCPs) Maximum look ahead time 0-255 mins 15-1200 mins TCP location Yes (sequence of bearing and Yes (Latitude and longitude) distance from start point) TCP altitude Yes Yes TCP time Yes Yes TCP speed No Yes TCP waypoint name (if appl.) No Yes TCP type specification No Yes Level change, e.g. Top of Climb Yes Yes (TOC) / Top of Descent (TOD) Lateral change Yes Yes Speed change start Implementation dependent (at least Yes Speed change end one of two provided) Yes Crossover No Yes Waypoint Depends if coincides with lateral/vertical/speed change Yes Fly-by turn radius No Yes Fly-over turn radius/radii No No Supports Radius to Fix (RF) legs No Yes Add. Data Gross mass No Yes
Problem Solved? The EPP unambiguously defined speed intent data (including speed changes), and allowed for accurate reconstruction of the lateral path, except for fly-over waypoints as the current EPP standard does not include turn radii for these manoeuvres. 2 Problem of trajectory synchronisation solved? 2 BRONSVOORT, J., MCDONALD, G., HOCHWARTH, J, & GALLO, E. (2014). AIR TO GROUND TRAJECTORY SYNCHRONISATION THROUGH EXTENDED PREDICTED PROFILE (EPP): A PILOT STUDY. PROCEEDINGS OF THE 14TH AIAA AVIATION TECHNOLOGY, INTEGRATION, AND OPERATIONS CONFERENCE, ATLANTA, USA
Test Scenario 1 Brisbane (YBBN) to Melbourne (YMML) RNAV SID RWY01 Published Route RNAV STAR with RNP transition to RWY34 B737-500 Cost Index 60 YBBN YMML
Simulation Process GE FMS Simulator Boeing Aircraft Intent Description Language (AIDL) Airservices Dali Trajectory Modeller (BADA4) SID Flight Plan GE FMS Simulator Reference Trajectory IPI EPP Translator IPI to AIDL Translator EPP to AIDL Translator Dali Trajectory Predictor Ground Trajectory STAR????
Results Scenario 1 2.2NM
Test Scenario 2 Brisbane (YBBN) to Melbourne (YMML) RNAV SID RWY01 Published Route RNAV STAR with RNP transition to RWY34 B737-500 Cost Index 60 Derate take-off & climb YMML YBBN
Results Scenario 2 7.5NM
Test Scenario 3 Brisbane (YBBN) to Melbourne (YMML) RNAV SID RWY01 Published Route RNAV STAR with RNP transition to RWY34 B737-500 Cost Index 60 Derate Take-off & Climb 5% Drag Factor YMML YBBN
Results Scenario 3 15NM 2500ft
Problem EPP provides the ability to synchronise lateral, speed and altitude intent. But no thrust intent as climb rating, anti-ice and high-idle. unknown aircraft performance characteristics such as drag factor. Lots of variables! Inclusion of all into EPP impractical bandwidth requirements. Confidential or proprietary information.
Calibration Torres et al (2011) 3 EPP was used to derive average vertical rate between EPP points to update ground performance tables Kinematic approach Only works for single down-linked instance of EPP synchronises trajectory What if we could use EPP to synchronise the trajectory prediction process rather than a single trajectory? 3 TORRES, S., KLOOSTER, J., HOCHWARTH, J., SUBBU, R., CASTILLO-EFFEN, M., & REN, L. (2011). TRAJECTORY SYNCHRONIZATION BETWEEN AIR AND GROUND TRAJECTORY PREDICTORS. PROCEEDINGS OF THE 30TH DIGITAL AVIONICS SYSTEMS CONFERENCE, SEATTLE.
Calibration (2) EPP allows for practically unambiguous description of aircraft intent Weather models can be accounted for by two-stage approach 4 Kinetic calibration of aircraft performance model m V g sin c T D APM TAS TAS EPP Trajectory Predictor Aircraft Intent Initial Conditions Trajectory Engine (TE) Aircraft Performance Model (APM) Weather Model (WM) Predicted Trajectory 4 BRONSVOORT, J. (2014). CONTRIBUTIONS TO TRAJECTORY PREDICTION THEORY AND ITS APPLICATION TO ARRIVAL MANAGEMENT FOR AIR TRAFFIC CONTROL. SUBMITTED TO DEPARTAMENTO DE SEÑALES, SISTEMAS Y RADIOCOMUNICACIONES. ESCUELA TÉCNICA SUPERIOR DE INGENIEROS DE TELECOMUNICACIÓN, UNIVERSIDAD POLITÉCNICA DE MADRID, MADRID.
Calibration (3) Nominal mass from EPP Nominal A/C performance from BADA Optimization process to find c for each EPP segment Dali Trajectory Predictor T D V g sin c TAS TAS EPP m EPP APM EPP2 EPP1
Results Nominal with Calibration 1.1NM NOMINAL EPP TRAJECTORY ALTITUDE BAND [FT] C [-] 0 2127 1 2127 3466 1.00 3466 9292 0.97 9292 9661 1.03 9661 10000 1.04 10000 10355 1.00 10355 10896 1.01 10896 23013 0.99 23013 25452 0.98 25452 32000 0.99
Results Derate with Calibration 1.0NM EPP TRAJECTORY WITH DERATE ALTITUDE BAND [FT] C [-] 0 2113 1 2113 3044 0.72 3044 7480 0.72 7480 7958 0.78 7958 8991 0.82 8991 10000 0.83 10000 11156 0.84 11156 21768 0.96 21768 25452 0.97 25452 32000 0.99
Results Derate & Drag Factor (Calb) 1.3NM EPP TRAJECTORY WITH DERATE & DRAG FACTOR ALTITUDE BAND [FT] C [-] 0 2116 1 2116 3017 0.74 3017 7327 0.70 7327 7827 0.77 7827 8781 0.76 8781 10000 0.82 10000 11228 0.82 11228 21174 0.91 21174 25452 0.90 25452 32000 0.88
Application Ground Trajectory based on nominal EPP with derate
Application Trial trajectory for 280KIAS without calibration
Application Trial trajectory for 280KIAS with calibration
Application Confirmed by new EPP down-link Confirmed by new EPP down-link
Conclusion Not all variables that impact the air-ground trajectory synchronisation process are included in the current EPP definition (DO-350/ED-228). It is impractical to include all these variables into a trajectory down-link definition, therefore real-time calibration will be essential for effective trajectory negotiation and management. With a single EPP down-link, the trajectory prediction process can be synchronised through a calibration function, ensuring high accuracy what-if trajectories and thereby anticipating the FMS behaviour upon changes in aircraft intent. EPP + Real-Time Calibration = Trajectory Synchronisation
Thank you Flying has torn apart the relationship of space and time: it uses our old clock but with new yardsticks. Charles A. Lindbergh.
Back-Up Slides
AIDL Generation Climb Cruise Segment AIDL Constant HS(CAS/M) Speed targets provided EPP by trajectory change Speed TL(MCMB) points. Acceleration EL(ESF) TL(MCMB) Acceleration segment fully defined by speed change start and end point in the EPP. Energy share factor be determined. Segment AIDL Cruise HS(M) HA(PRE) Altitude and speed provided by EPP trajectory change points. TOC and TOD trajectory change points identified. 128 points visible. Descent Segment AIDL Pseudo-idle at HS(CAS/M)* Speed targets provided EPP by trajectory change constant speed HPA(GEO) points. Altitude profile well established with all relevant trajectory change points present in the EPP. Deceleration SL(CAS/M)* HPA(GEO) Deceleration segment defined by speed change start and end point in the EPP. Speed law to model deceleration can be determined from these EPP points.