NASA Langley Distributed Propulsion VTOL TiltWing Aircraft Testing, Modeling, Simulation, Control, and Flight Test Development

Rothhaar, Paul M.; Murphy, Patrick C.; Bacon, Barton J.; Gregory, Irene M.; Grauer, Jared A.; Busan, Ronald C.; Croom, Mark A.

doi:10.2514/6.2014-2999

Cited by 78 publications

(43 citation statements)

References 8 publications

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“…These data confirmed the aircraft designer's expectation that a stall break would occur in the 10° to 15° angle of attack range and lift would be well maintained after stall 10 . Since aerodynamic coefficients are very strong functions of angle of attack and sideslip, the data supported a separate low range test below 10° alpha for the cruise mode.…”

Section: Aerodynamic Behavior and Hysteresis Checksupporting

confidence: 86%

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Experiment Design for Complex VTOL Aircraft with Distributed Propulsion and Tilt Wing

Murphy

Landman

2015

AIAA Atmospheric Flight Mechanics Conference

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Selected experimental results from a wind tunnel study of a subscale VTOL concept with distributed propulsion and tilt lifting surfaces are presented. The vehicle complexity and automated test facility were ideal for use with a randomized designed experiment. Design of Experiments and Response Surface Methods were invoked to produce run efficient, statistically rigorous regression models with minimized prediction error. Static tests were conducted at the NASA Langley 12-Foot Low-Speed Tunnel to model all six aerodynamic coefficients over a large flight envelope. This work supports investigations at NASA Langley in developing advanced configurations, simulations, and advanced control systems. Bi = regression coefficients CN = normal force coefficient Cm = pitching-moment coefficient = mean aerodynamic chord, ft R 2 = multiple correlation coefficent xi = regressors α = angle-of-attack, deg β = sideslip angle, deg σ = standard error Abbreviations ANOVA = Analysis of Variance BWB = Blended Wing Body CCD = Central Composite Design DEP = Distributed Electric Propulsion DOE = Design of Experiments FCD = Face-Centered Design ME = Main Effects OFAT = One Factor At a Time RSM = Response Surface Modeling VIF = Variance Inflation Factor VTOL = Vertical Takeoff & Landing 2FI = Two-factor Interaction Aircraft Factors aoa = aircraft angle of attack, deg beta = aircraft sideslip, deg LWS1 = left wing outboard surface, deg LWS2 = left wing middle surface, deg LWS3 = left wing inboard surface, deg RWS4 = right wing inboard surface, deg RWS5 = right wing middle surface, deg RWS6 = right wing outboard surface, deg LTS1 = left tail elevator, deg RTS2 = right tail elevator, deg Ttilt = horizontal tail position, deg Wtilt = wing position, deg Rud = rudder position, deg LWEi = left wing engine i=1-4, rpm RWEj = right wing engine j=5-8, rpm LTE1 = left tail engine, rpm RTE2 = right tail engine, rpm American Institute of Aeronautics and Astronautics 1 Downloaded by UNIVERSITY OF IOWA on July 30, 2015 | http://arc.aiaa.org |

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Section: Aerodynamic Behavior and Hysteresis Checksupporting

confidence: 86%

“…Details of the GL-10 design and development are described in Refs. [8][9][10]. The design capitalizes on a distributed electric propulsion system that allows thrust to be applied across the airframe without mechanical complexity and allows a broad scale-free range for the designer.…”

Section: Introductionmentioning

confidence: 99%

Experiment Design for Complex VTOL Aircraft with Distributed Propulsion and Tilt Wing

Murphy

Landman

2015

AIAA Atmospheric Flight Mechanics Conference

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“…(40) has to be transformed into the output feedback form by using the following controller order reduction technique. First, define a weighted output vector as 1 …”

Section: Control Augmentation System Designmentioning

confidence: 99%

“…In recent years, a study of VTOL aircraft has attracted renewed attention. NASA and Defense Advanced Research Projects Agency (DARPA) have been started their programs to develop a next generation or advanced VTOL aircraft 1,2 .…”

Section: Introductionmentioning

confidence: 99%

Design of Gain Scheduled Stability and Control Augmentation System for Quad-Tilt-Wing UAV

Totoki

Ochi

Sato

et al. 2015

AIAA Guidance, Navigation, and Control Conference

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This paper describes design of a stability and control augmentation system (SAS and CAS) for a small prototype quad-tilt-wing (QTW) unmanned aerial vehicle (UAV) developed by Japan Aerospace Exploration Agency (JAXA). Since the dynamics of QTW is originally unstable at most of the tilt angles in the both longitudinal and lateral-directional motions, stabilizing control is necessary for the practical operations. In this paper, a gain scheduled PD-SAS is designed by solving linear matrix inequalities (LMIs) formulated for a static output feedback problem. In addition to SAS, CAS is designed to improve the pilot handling. The CAS is derived based on an integral-type optimal servomechanism and controller order reduction technique. Both the controller gains are scheduled with the tilt angles, since the dynamic characteristics of QTW change widely according to the tilt angles. Nonlinear human-in-the-loop simulation results have shown that the obtained gain scheduled controllers stabilize the QTW in almost all the tilt angles and provide good tracking performance for the attitude commands. NomenclatureA p_i = system matrix of QTW model A c_i = system matrix of linearized PFCS model B p_i = input matrix of QTW model B c_i = input matrix of linearized PFCS model C p_i = measurement matrix of QTW model C c_i = measurement matrix of linearized PFCS model u,v,w = velocity of QTW along body axis p,q,r = angular velocity T d = time constant of PD controller τ w = tilt angle, deg stick θ δ = pitch stick input from remote ground pilot, % clc δ = collective stick input from remote ground pilot, % stick Φ δ = roll stick input from remote ground pilot, % stick Ψ δ = yaw stick input from remote ground pilot, % θ = pitch angle φ = bank angle Q y , Q u = weighting matrix 0 Γ = optimal value of a performance index

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“…17 The concept of tilted rotors to circle-wise for hex-rotor UAVs was proposed by Jiang and Voyles. 18 The aim of the configuration was to implement six degrees of freedom actuation for multi-rotor control.…”

Section: Introductionmentioning

confidence: 99%

Reduction of the head-up pitching moment of small quad-rotor unmanned aerial vehicles in uniform flow

Otsuka

Sasaki

Nagatani

2017

International Journal of Micro Air Vehicles

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Multi-rotor unmanned aerial vehicles are unstable in headwind because of nose-up pitching moment generation and thrust degradation. Reducing the pitching moment generation could enhance the tolerance of the unmanned aerial vehicles to wind and improve cruise flight speed. In this study, a canted rotor configuration was proposed to reduce the moment in uniform flow and examined. The objective of the study is to evaluate the effect of moment reduction by canted rotors. First, flow interactions between rotors of the quad-rotor were visualized using a smoke wire method. Second, the moment reduction by canted rotors was estimated based on isolated rotor performance. Third, the moment of the quad-rotor varying the body pitching angle was examined using a wind tunnel. At an 8 m/s wind, when the body pitching angle is horizontal, slanting the rotor by 20 to outside the body degraded the moment by 26% compared with the parallel rotor configuration.

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NASA Langley Distributed Propulsion VTOL TiltWing Aircraft Testing, Modeling, Simulation, Control, and Flight Test Development

Cited by 78 publications

References 8 publications

Experiment Design for Complex VTOL Aircraft with Distributed Propulsion and Tilt Wing

Experiment Design for Complex VTOL Aircraft with Distributed Propulsion and Tilt Wing

Design of Gain Scheduled Stability and Control Augmentation System for Quad-Tilt-Wing UAV

Reduction of the head-up pitching moment of small quad-rotor unmanned aerial vehicles in uniform flow

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