Spatial disorientation (SD) is a dangerous occurrence that may cause the crash of the aircraft. During SD, the pilot has a wrong perception of the aircraft’s attitude. An Automatic Recovery System is a Flight Control System feature that takes control of the aircraft during such events. AleniaAermacchi spa is currently developing an ARS for its M346 “Master” in the form of a Pilot-Activated Recovery System (PARS).
The optimal recovery manoeuvres were obtained in this thesis to be compared against the PARS manoeuvres. This comparison has the objective of evaluating the performance of the PARS generated recovery manoeuvres and recovery strategies

MANNUCCI, TOMMASO

Electronic Thesis and Dissertation Archive - Università di Pisa

  UNIVERSITÀ DI PISA FACOLTÀ DI INGEGNERIA  CORSO DI LAUREA SPECIALISTICA IN INGEGNERIA AEROSPAZIALE      TESI DI LAUREA SPECIALISTICA Sviluppo e convalida della funzionalità di Automatic Disorientation Recovery per un velivolo ad elevate prestazioni Relatori:   Prof. Ing. Eugenio Denti  Ing. Francesco Nasuti   Candidato:  Tommaso Mannucci    ANNO ACCADEMICO 2011 - 2012  i              Summary     Spatial disorientation (SD) is a dangerous occurrence that may cause the crash of the aircraft. During SD, the pilot has a wrong perception of the aircraft’s attitude. An Automatic Recovery System is a Flight Control System feature that takes control of the aircraft during such events. AleniaAermacchi spa is currently developing an ARS for its M346 “Master” in the form of a Pilot-Activated Recovery System (PARS).     Alternative optimal recovery manoeuvres were obtained in this thesis to be compared against the PARS manoeuvres. This comparison has the objective of evaluating the performance of the PARS generated recovery manoeuvres and recovery strategies.                      ii Index:  1 Introduction ................................................................................................................................. 1 1.1 Scenario.................................................................................................................................. 1 1.2 Thesis contribution ................................................................................................................ 2 1.3 Structure of the thesis ........................................................................................................... 2 2 Automatic Recovery Systems ....................................................................................................... 4 2.1 Overview ................................................................................................................................ 4 2.2 M346 PARS ............................................................................................................................. 6 2.2.1 The M346 “Master” ...................................................................................................... 6 2.2.2 Functional description .................................................................................................. 7 2.2.3 Pilot interaction ............................................................................................................ 7 2.2.4 Recovery strategies ...................................................................................................... 9 2.2.5 Demand and equivalent stick command computation .............................................. 11 2.2.6 Envelope coverage ..................................................................................................... 12 3 Trajectory Optimization problem .............................................................................................. 14 3.1 Introduction ......................................................................................................................... 14 3.2 Definition of the problem .................................................................................................... 14 3.3 Optimal Control Theory ....................................................................................................... 15 3.4 Indirect methods .................................................................................................................. 17 3.4.1 Indirect Shooting Method .......................................................................................... 17 3.4.2 Indirect Multiple-Shooting method ........................................................................... 18 3.4.3 Overview of Indirect methods .................................................................................... 19 3.5 Direct methods .................................................................................................................... 19 3.5.1 Non-Linear Programming ........................................................................................... 19 3.5.2 Direct Shooting and Direct Multiple-Shooting methods ............................................ 21 3.5.3 Direct Collocation method ......................................................................................... 23 3.5.4 Overview of Direct methods ...................................................................................... 24 3.6 Solving the NLP problem ...................................................................................................... 24 3.6.1 Sequential Quadratic Programming ........................................................................... 26 4 Optimization tools ...................................................................................................................... 29 4.1 Choice of tools ..................................................................................................................... 29 4.1.1 GPOPS ......................................................................................................................... 29 4.1.2 ICLOCS with NLP solver Ipopt ..................................................................................... 29 4.2 Tools application .................................................................................................................. 30 4.3 Examples .............................................................................................................................. 31 4.3.1 The Boat problem ....................................................................................................... 31 4.3.2 The Missile problem ................................................................................................... 33 5 The performance index function ............................................................................................... 37 5.1 Optimality definition ............................................................................................................ 37 5.1.1 Quickness index .......................................................................................................... 38 5.1.2 Safety index ................................................................................................................ 38 5.1.3 Comfort index ............................................................................................................. 39 5.2 Choice of coefficients ........................................................................................................... 40 5.3 Sample manoeuvres for performance index ....................................................................... 42 5.3.1 Nose-up recovery ....................................................................................................... 42 5.3.2 Nose-down recovery .................................................................................................. 44 5.3.3 Low speed recovery .................................................................................................... 44   iii 6 Dynamic model .......................................................................................................................... 47 6.1 Choice of model ................................................................................................................... 47 6.1.1 Complete model ......................................................................................................... 47 6.1.2 Simplified model ......................................................................................................... 48 6.2 Differences between models ............................................................................................... 51 7 Results ........................................................................................................................................ 55 7.1 Presentation of the results .................................................................................................. 55 7.1.1 Initial conditions choice .............................................................................................. 55 7.1.2 Comparative plots ...................................................................................................... 56 7.1.3 Results evaluation ...................................................................................................... 57 8 Conclusions ................................................................................................................................ 70 Bibliography ....................................................................................................................................... 71 Acknowledgements ............................................................................................................................ 73 Appendix A: Simplified model overview ............................................................................................ 74 Appendix B: Simplified model validation ........................................................................................... 79 Appendix C: Plots of the recovery manoeuvres................................................................................. 87                          iv  List of Acronyms    ADRS Automatic Disorientation Recovery System AoA Angle of Attack ARS Automatic Recovery System DoF Degree of Freedom EAS Equivalent Air Speed EQP Equality Quadratic Programming FCS Flight Control System GCAS Ground Collision Avoidance System GPWS Ground Proximity Warning System HF Human Factor KEAS Equivalent Air Speed in knots LM Lagrange Multiplier NLP Non-Linear Programming OCT Optimal Control Theory PARS Pilot-Activated Recovery System QP Quadratic Programming RR Roll Rate SD Spatial Disorientation SQP Sequential Quadratic Programming TO Trajectory Optimization 

Sviluppo e convalida della funzionalita' di Automatic Disorientation Recovery per un velivolo ad elevate prestazioni

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