Characterizing Wing Rock with Variations in Size and Configuration of Vertical Tail

Johnson, Baron; Lind, Rick

doi:10.2514/1.45719

Cited by 22 publications

(12 citation statements)

References 21 publications

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“…The aircraft is produced and distributed by Hangar 9 TM , and a scaled-down variant has been examined recently in experiments designed to study wing rock. 34 As seen in Fig. 3, the 1.45-m (57-in) wingspan aircraft has wing side-force generators (which are optional) for greater performance in knife-edge flight.…”

Section: A Wing Aerodynamicsmentioning

confidence: 98%

“…When upright for the first ≈27 deg, the aircraft is more unsteady and difficult to fly; whereas, when inverted the excursions are reduced. In real observations, upright harrier flight of model-scale aircraft are known to wing rock, 34 and this characteristic is partly captured by the simulation as demonstrated here in the time histories.…”

Section: E Upright and Inverted Harrier Sequencementioning

confidence: 98%

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Modeling Full-Envelope Aerodynamics of Small UAVs in Realtime

Selig

2010

AIAA Atmospheric Flight Mechanics Conference

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This paper focuses on full six degree-of-freedom (6-DOF) aerodynamic modeling of small UAVs at high angles of attack and high sideslip in maneuvers performed using large control surfaces at large deflections for aircraft with high thrust-to-weight ratios. Configurations such as this include many of the currently available propellerdriven RC-model airplanes that have control surfaces as large as 50% chord, deflections as high as 50 deg, and thrust-to-weight ratios near 2:1. Airplanes with these capabilities are extremely maneuverable and aerobatic, and modeling their aerodynamic behavior requires new thinking because using traditional stability derivative methods is not practical with highly nonlinear aerodynamic behavior and coupling in the presence of high propwash effects. The method described in this paper outlines a component-based approach capable of modeling these extremely maneuverable small UAVs in a full 6-DOF realtime environment over the full envelope that is defined in this paper to be the full ±180 deg range in angle of attack and sideslip. This method is the foundation of the aerodynamics model used in the RC flight simulator FS One. Piloted flight simulation results for four small RC/UAV configurations having wingspans in the range 826 mm (32.5 in) to 2540 mm (100 in) are presented to highlight results of the high-angle aerodynamics modeling approach. Maneuvers simulated include tailslides, knife edge flight, high-angle upright and inverted flight ("harriers"), rolling maneuvers at high angle ("rolling harriers") and an inverted spin of a biplane ("blender"). For each case, the flight trajectory is presented together with time histories of aircraft state data during the maneuvers, which are discussed. Nomenclature,c/4 = moment coefficient about quarter chord D = drag; propeller diameter J = propeller advance ratio based on V N L = lift M = pitching moment about y-axis (positive nose up) n = propeller rotational speed (revs/sec) * Associate Professor, Department of Aerospace Engineering, 104 S. Wright St. Senior Member AIAA.= propeller yawing moment due to angle of attack p, q, r = roll, pitch and yaw rate P N = propeller normal force due to angle of attack Q = propeller axial torque q = dynamic pressure (ρV 2 /2) R = propeller radius S = reference area T = propeller axial thrust u, v, w = components of the local relative flow velocity along x, y, z, respectively V = flow velocity x, y, z = body-axis coordinates, +x out nose, +y out right wing, +z down y c = airfoil camber TED = trailing edge down TEL = trailing edge left TEU = trailing edge up Subscripts N = normal component R = relative component Symbols α = angle of attack (arctan(w/u)) β = sideslip angle (arcsin(v/V )) β ′ = angle of attack for vertical surface (arctan(v/u)) δ a = aileron deflection [(δ a,r − δ a,l )/2], right +TEU, left +TEU δ e = elevator deflection, +TED δ r = rudder deflection, +TEL ǫ = wing induced angle of attack η s = dynamic pressure ratio for flow shadow (shielding) effect φ, θ, ψ = bank angle, pitch angle, heading angl...

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Section: A Wing Aerodynamicsmentioning

confidence: 98%

Section: E Upright and Inverted Harrier Sequencementioning

confidence: 98%

Modeling Full-Envelope Aerodynamics of Small UAVs in Realtime

Selig

2010

AIAA Atmospheric Flight Mechanics Conference

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“…On a larger scale and outdoors, the wing rock characteristics of a medium sized Radio Control (RC) hobby aircraft flying at high angles of attack were studied by Lind and Johnson [13]. The aircraft was flown open loop by a RC pilot through multiple passes during which it experienced uncommanded wing rock.…”

Section: Introductionmentioning

confidence: 99%

Aerodynamic Sensing for a Fixed Wing UAS Operating at High Angles of Attack

Shyy

Bernal

Yeo

et al. 2012

AIAA Atmospheric Flight Mechanics Conference

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The flight profile of typical small unmanned air systems (UAS) has expanded in the last decade beyond those encountered by traditional fixed-wing transport and rotary-wing aircraft. These new flight conditions may involve unusual flight mechanics as with flapping wing flight or complex aerodynamics when performing difficult maneuvers as part of routine operations. Such scenarios typically involve unsteady and inherently non-linear aerodynamics that challenge current autopilots relying primarily on inertial measurements and GPS data. The addition of aerodynamic feedback to the current UAS sensing and control framework can enable the autopilots of aircraft operating under such conditions to better achieve their control objectives and expand their autonomous flight capabilities. This paper describes the ongoing development of a pressurebased aerodynamic data system for a fixed wing UAS operating at high angles of attack. Expansions to the aerodynamic instrumentation package based on flight test results are described. These include an expanded set of wing pressure ports and a custom designed multi-hole probe for prop-wash estimation. Autonomous flight test data from the first generation UAS system transitioning between cruise and hover are presented and discussed. Open loop flight data acquired using the upgraded sensing concept is then presented. Flight test results show that the sensing package provides data that is complementary to a typical Inertial Measurement Unit and can support the development of feedback control strategies based on aerodynamic measurements.

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“…10,[22][23][24] The RCAT System and Eagle Tree Systems units seem to be the only data recording devices currently available with a small enough form factor to allow them to be installed in a small to mid-sized UAV without being a major hindrance. The specifications for these units are given in Table 3.…”

Section: A Literature Review Of Data Acquisition Systems For Small Tmentioning

confidence: 99%

High-Frequency Sensor Data Acquisition System (SDAC) for Flight Control and Aerodynamic Data Collection

Dantsker

Mancuso

Selig

et al. 2014

32nd AIAA Applied Aerodynamics Conference

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This paper describes a high-frequency sensor data acquisition system (SDAC) for flight control and aerodynamic data collection research on small to mid-sized unmanned aerial vehicles (UAVs). The system is both low weight and low power, operates at 100 Hz and features: a high-frequency, high-resolution six degree-offreedom (6-DOF) inertial measurement unit (IMU) with a global positioning system (GPS) receiver, a 3-axis magnetometer, a pitot probe, seven 10-bit analog-to-digital converters (ADC), sixteen 12-bit analog-to-digital converters, a 14-bit analog-to-digital converter, twenty digital input/outputs (I/O), eight pulse width modulation (PWM) signal inputs, a 40 mile downlink transceiver, an open serial and an open CANbus port, and up to 64 GB of onboard storage. The data acquisition system was completely fabricated from commercial-off-theshelf (COTS) components, which reduced the system cost and implementation time. The SDAC combines the large variety of sensor streams into a unified high-fidelity state data stream that is recorded for later aerodynamics analysis and simultaneously forwarded to a separate processing unit, such as an autopilot.

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Characterizing Wing Rock with Variations in Size and Configuration of Vertical Tail

Cited by 22 publications

References 21 publications

Modeling Full-Envelope Aerodynamics of Small UAVs in Realtime

Modeling Full-Envelope Aerodynamics of Small UAVs in Realtime

Aerodynamic Sensing for a Fixed Wing UAS Operating at High Angles of Attack

High-Frequency Sensor Data Acquisition System (SDAC) for Flight Control and Aerodynamic Data Collection

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