The ARISTOTEL project Aircraft and Rotorcraft Pilot

Transcription

1 The ARISTOTEL project Aircraft and Rotorcraft Pilot Couplings Tools and Techniques for Alleviation and Detection General presentation

2 Background of ARISTOTEL Aristotel, Aristotle, Aristoteles (384 BC 322 BC) Greek philosopher, a student of Plato and teacher of Alexander the Great. Detail from The School of Athens, Raphael ARISTOTEL = Aircraft and Rotorcraft Pilot Couplings Tools and Techniques for Alleviation and Detection Collaborative project funded under the European Community s 7 th Framework Programme Workshop A/RPCs Milano March 9,

3 Facts and figures Acronym: ARISTOTEL - Aircraft and Rotorcraft Pilot Couplings Tools and Techniques for Alleviation and Detection Grant Agreement: Instrument: CP FP Total cost: 3,843, EU funding: 3,003,652 Call: FP7 AAT 2010 RTD 1 Start date: End date: Duration: 36 months Technical domain: Ensuring Customer Satisfaction and Safety Website: Workshop A/RPCs Milano March 9,

4 The ARISTOTEL Consortium Technische Universiteit Delft - Coordinator Wytwornia Sprzetu Komunikacy Jnego PZL- Swidnik Spolka Akcyjna Office National d'etudes et de Recherches Aerospatiales The University of Liverpool SC Straero SA Politecnico di Milano Universita degli Studi Roma Tre Federal State Unitary Enterprise The Central Aerohydrodynamic Institute named after Prof. N.E. Zhukovsky Stichting Nationaal Lucht- en Ruimtevaartlaboratorium Workshop A/RPCs Milano March 9, 2011 European Research and Project Office GmbH 4

5 EU set a joint initiative to cut aviation accidents by 80% in 2020 The understanding, controlling and suppressing of pilot s involuntary participation is a demanding problem for actual aircraft with high bandwidth servo hydraulic actuation systems and enlarged operational ranges. A/RPCs are still a matter of high concern for safety. Modern designs seem even more sensitive to A/RPCs Rotorcraft RPCs are significantly more problematic than aircraft APCs. We hardly possess guidelines for designing A/RPCs free configurations. Workshop A/RPCs Milano March 9,

6 The ARISTOTEL key problems KEY PROBLEM 1 Lack of understanding what A/RPC is KEY PROBLEM 2 Lack of specific A/RPC pilot models KEY PROBLEM 6 No coherent design guide for A/RPC The ARISTOTEL project KEY PROBLEM 3 Lack of proper A/RPC vehicle models KEY PROBLEM 5 No proper simulator practices to unmask A/RPC KEY PROBLEM 4 No reliable A/RPC criteria Workshop A/RPCs Milano March 9,

7 The ARISTOTEL ambition OBJECTIVE 1 Develop understanding & definition of A/RPC OBJECTIVE 2 Develop advanced pilot models for A/RPC analysis OBJECTIVE 6 Develop coherent design guide The ARISTOTEL project OBJECTIVE 3 Develop advanced vehicle models for aircraf/rotorcraft OBJECTIVE 5 Develop protocols for simulator training OBJECTIVE 4 Develop, extend, improve current A/RPC criteria Workshop A/RPCs Milano March 9,

8 WP6 Dissemination & Exploitation The ARISTOTEL Work Plan WP1 Anatomy of APC/RPC WP2 Rigid body RPC WP3 Aero-servo-elastic A/RPC WP4 Testing and validation for A/RPC WP7 Management WP5 Design guidelines and methodologies for A/RPC prevention Workshop A/RPCs Milano March 9,

9 What is A/RPC? Fixed and rotary wing pilots alike are familiar with potential instabilities or with annoying limit cycle oscillations that arise from controlling aircrafts with high response actuation systems. Flight control system Aircraft/Rotorcraft Pilot A/RPC (PIO/PAO) = "Inadvertent, sustained aircraft oscillations which are a consequence of an abnormal joint enterprise between the aircraft and the pilot" (McRuer et al., 1997) Workshop A/RPCs Milano March 9,

10 What is A/RPC? Definition developed in ARISTOTEL: "An Aircraft- or Rotorcraft-Pilot Coupling (A/RPC) is an unintentional (inadvertent) sustained or uncontrollable vehicle oscillations characterized by a mismatch between the pilot s mental model of the vehicle dynamics and the actual vehicle dynamics. The result is that the pilot's control input is out-of-phase with the response of the vehicle, possibly causing a diverging motion." Workshop A/RPCs Milano March 9,

11 Aircraft/Rotorcraft Pilot couplings with PIO Pilot induced oscillations Physics: A/RPCs occur when the pilot inadvertently excites divergent vehicle oscillations by applying control inputs that are in the wrong direction or have phase lag. Since active involvement in the control loop is occurring, A/RPCs will cease when the pilot releases the controls, stops control motion or changes control strategy. Examples at helicopters: Excitation of low -damped main rotor regressive inplane mode by cyclic stick inputs resulting in body roll and pitch aircraft vibrations. Excitation of low frequency pendulum mode of external slung loads by delayed collective and/or cyclic control inputs due to couplings of the load dynamics via elastic cables. Workshop A/RPCs Milano March 9,

12 Well known Problems of Unintended RPC at helicopters Inplane Forces Vertical Forces, Torque Source: Cyclic control inputs Problem: Resonance excitation of inplane regressive/blade bending modes Blade strength limits Source: Collective control inputs Problem: Resonance excitation of tailboom bending and drive train modes, respectively Comfort & strength limit Source: Eurocopter, Garteur work PIO Workshop A/RPCs Milano March 9,

13 Aircraft/Rotorcraft Pilot couplings à la PAO Pilot assisted oscillations Physics: A/RPC s are the result of involuntary control inputs of the pilot in the loop that may destabilize the aircraft due to inadvertent man - machine couplings. Since passive involvements by the pilot s biodynamic response to vibrations occur, these oscillations are generally much more dangerous because releasing the controls may be impossible. Examples at helicopters: Destabilization of the main rotor blade bending torsion motion at high rotor loadings and flight speeds during manoeuvres by stall effects results in airframe vibrations which may be amplified by unintended cyclic stick inputs of the pilot. Destabilization of low-damped main rotor engine drive train modes aggravated by pilot assisted collective control inputs. Augmentation of transient airframe bending oscillation by feedback type couplings of the airframe structure by the main rotor via the actuation system assisted by collective and/or cyclic control inputs. Workshop A/RPCs Milano March 9,

14 Division of A/RPCs A/RPCs in Flight Mechanics Associated with flight mechanical frequencies Related to high control sensitivities (e.g. about roll axis) Attributed to an overlap of guidance and control task A/RPCs in Dynamics/Aeroelastics Associated with structural dynamics or aeroelastic resonances Supported by high bandwidth servo-hydraulic control systems Workshop A/RPCs Milano March 9,

15 Simulators TUD Helicopters Fixed wing Bio-dynamical tests NLR LIVERPOOL TSAGI 4 test campaigns for bio-dynamical research and 4 test campaigns for simulators have been planned. Workshop A/RPCs Milano March 9,

16 Multitude of configurations Fly-by-wire sidestick flight deck Future large transport aircraft Conventional wheel/column flight deck Relation between the next generation cockpit control configurations and pilot-vehicle interaction for prevention of large transport aircraft APC and rotorcraft RPC Workshop A/RPCs Milano March 9,

17 Example of Biodynamic Feedthrough Tests Biodynamic feedthrough (BDFT) = the phenomenon where vehicle accelerations can cause involuntary pilot control inputs CNS HO CD CE PLF NMS CD : Control Device CE : Controlled Element PLF: Platform HO : Human Operator NMS : Neuromuscular System CNS : Central Nervous System Workshop A/RPCs Milano March 9,

18 Example of Biodynamic Feedthrough Tests Recent results of BDFT tests: BDFT is task dependent Neuromuscular admittance Biodynamic feedthrough compliant high feedthrough stiff low feedthrough Joost Venrooij et. Al. (2010) Workshop A/RPCs Milano March 9,

19 ARISTOTEL Ascent from the study of particular phenomena to the knowledge of essences Like Aristotle, we hope to find the "universal" in particular things - the essence of things -