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Dissertations / Theses on the topic 'Helicopters'

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Published: 4 June 2021
Last updated: 29 July 2024

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1

Peitso, Loren E. "Visual field requirements for precision nap-of-the-earth helicopter flight." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FPeitso.pdf.

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Thesis (M.S. in Modeling, Virtual Environments and Simulation)--Naval Postgraduate School, September 2002.
Thesis advisor(s): Rudolph P. Darken, Joe Sullivan. Includes bibliographical references (p. 65-66). Also available online.
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2

Perkins, Keith M. "Implementing realistic helicopter physics in 3D game environments." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FPerkins.pdf.

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Thesis (M.S. in Modeling, Virtual Environments and Simulations)--Naval Postgraduate School, September 2002.
Thesis advisor(s). Includes bibliographical references (p. 79-80). Also available online.
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3

Cook, Jeffrey S. "Analysis of consolidation of intermediate level maintenance for Atlantic Fleet T700-GE-401 engines." Thesis, Monterey, Calif. : Naval Postgraduate School, 1992. http://handle.dtic.mil/100.2/ADA257754.

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4

Ference, Edward W. "Case study of the development of the Apache attack helicopter (AH-64)." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Dec%5FFerence.pdf.

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Thesis (M.S. in Program Management)--Naval Postgraduate School, December 2002.
Thesis advisor(s): Michael W. Boudreau, Richard G. Rhoades. Includes bibliographical references (p. 63-65). Also available online.
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5

Howard, Christopher B. Bradley Walter Lee. "Fatigue methodology for analysis of helicopter dynamic components." Waco, Tex. : Baylor University, 2008. http://hdl.handle.net/2104/5188.

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6

Ozturk, Dogan. "Development of a Myklestad's rotor blade dynamic analysis code for application to JANRAD." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FOzturk.pdf.

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Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, September 2002.
Thesis advisor(s): E. Roberts Wood, Mark A. Couch. Includes bibliographical references (p. 213-214). Also available online.
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7

Van, Riper Steven G. "Investigation of increased forward flight velocities of helicopters using second harmonic control and reverse velocity rotor concept." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Dec%5FVanRiper.pdf.

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Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, December 2003.
Thesis advisor(s): E. Roberts Wood, Raymond Shreeve. Includes bibliographical references (p. 145-146). Also available online.
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8

Prichard, Devon S. "Development of a full potential solver for rotor aerodynamics analysis." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/12033.

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9

Schaefer, Carl George. "Enhanced energy maneuverability for attack helicopters using continuous, variable rotor speed control." Master's thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03302010-020156/.

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10

Wasikowski, Mark E. "An investigation of helicopter individual blade control using optimal output feedback." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/12387.

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11

Sturisky, Selwyn H. "A linear system identification and validaton of an AH-64 apache aeroelastic simulation model." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/13402.

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12

Teare, David Alan. "Modeling and system identification for rotorcraft." Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/17088.

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13

Su, Ay. "Application of a state-space wake model to elastic blade flapping in hover." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/11965.

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14

de, Andrade Donizeti. "Application of finite-state inflow to flap-lag-torsion damping in hover." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/12412.

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15

Khan, Azhar Mansur. "Helicopter mission and rotor performance optimization with quasi-linear inflow theory." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/12413.

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16

Berry, John D. "A method of computing the aerodynamic interactions of a rotor-fuselage configuration in forward flight." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/12936.

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17

Wang, Yi-Ren. "The effect of wake dynamics on rotor eigenvalues in forward flight." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/13031.

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18

Atilgan, Ali Rana. "Towards a unified analysis methodology for composite rotor blades." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/15403.

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19

Fitzsimons, Philip Matthew. "Design of a helicopter automatic flight control system using adaptive control." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/16641.

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20

Stettner, Martin. "Application of a state-space wake model to a servo flap controlled rotor in hover." Thesis, Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/20202.

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21

Rauchenstein, Werner J. "A 3D Theodorsen-based rotor blade flutter model using normal modes." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FRauchenstein.pdf.

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Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, September 2002.
Thesis advisor(s): E. Roberts Wood, Mark A. Couch. Includes bibliographical references (p. 55-56). Also available online.
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22

Kulakowski, Walter W. "Exploring the feasibility of the virtual environment helicopter system (VEHELO) for use as an instructional tool for military helicopter pilots." Thesis, Monterey, California. Naval Postgraduate School, 2004. http://hdl.handle.net/10945/1394.

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The requirement for low-level navigation flight conducted between 200 and 500 feet above ground level is something unique to the military helicopter pilot. Each novice helicopter pilot is introduced to this skill early and in a limited number of flights or flight hours. A low situational awareness (SA)is historically noted among the novice pilots during their first few flights within this flight regime. To that end, this thesis continues with the work conducted earlier to develop a trainer that places the pilot in an immersive and familiar cockpit environment for training through the use of chromakeyed technology as employed in the Virtual Environment Helicopter System (VEHELO). The pilot will then be able to learn and exercise required piloting tasks and multi-place aircraft communications as authentically and as meticulously as in actual flight. The focus of this thesis is to continue validation of the ChrAVE/VEHELO system. This will be accomplished by comparison of data obtained from data collected by pilots flying the ChrAVE and flying the actual aircraft during initial navigational training flights. Additionally this thesis will attempt to show that the latest version of the system has a previously unrecognized ability to improve pilot performance. The system is capable of teaching novice pilots the important skill of Crew Resource Management (CRM) and the appropriate communication skills. The original Chromakey Augmented Virtual Environment (ChrAVE) helicopter flight simulation system was developed to substantiate the feasibility of having embedded trainers for helicopters. Both the ChrAVE and VEHELO are comprised of commercial off the shelf (COTS) equipment in a mobile wheeled box. To determine the effectiveness of the ChrAVE as an instructional tool, the opinions of pilots and pilot instructors will be collected for analysis. The subject pilots will be tasked with numerous realistic piloting tasks. Empirical data will be collected and evaluated according to the low-level navigation performance thresholds set forth by Marine Medium Helicopter Training Squadron 164 (HMMT- 164) which is the CH-46E Model Manager.
US Marine Corps (USMC) author.
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23

Tai, Jimmy C. M. "A multidisciplinary design approach to size stopped rotor/wing configurations using reaction drive and circulation control." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/13460.

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24

Groenke, Andrew S. "CAS, interdiction, and attack helicopters." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Jun%5FGroenke.pdf.

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25

Xin, Hong. "Development and validation of a generalized ground effect model for lifting rotors." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/11880.

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26

Yoo, Kyung M. "Unsteady vortex lattice aerodynamics for rotor aeroelasticity in hover and in forward flight." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/11961.

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27

Lipp, Andreas Martin. "Modeling and nonlinear controller development for the apache helicopter using GTNONCON." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/12085.

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28

Taylor, Dana J. "A method for the efficient calculation of elastic rotor blade dynamic response in forward flight." Diss., Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/12396.

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29

Heiges, Michael W. "A helicopter flight path controller design via a nonlinear transformation technique." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/12482.

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30

Kaladi, Vasudevan M. "Unsteady compressible lifting surface analysis for rotary wings using velocity potential modes." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/12524.

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31

Boen, Gilbert E. "Application of approximation techniques to helicopter flight path optimization." Thesis, Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/13036.

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32

Wray, John D. "Optimizing helicopter assault support in a high demand environment." Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Jun/09Jun%5FWray.pdf.

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Thesis (M.S. in Operations Research)--Naval Postgraduate School, June 2009.
Thesis Advisor(s): Brown, Gerald ; Carlyle, Matthew. "June 2009." Description based on title screen as viewed on July 13, 2009. Author(s) subject terms: optimization, math programming, helicopter planning, assault support. Includes bibliographical references (p. 41). Also available in print.
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33

Collins, Kyle Brian. "A multi-fidelity framework for physics based rotor blade simulation and optimization." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26481.

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Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009.
Committee Co-Chair: Dr. Dimitri Mavris; Committee Co-Chair: Dr. Lakshmi N. Sankar; Committee Member: Dr. Daniel P. Schrage; Committee Member: Dr. Kenneth S. Brentner; Committee Member: Dr. Mark Costello. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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34

Pippin, Bradley W. "Allocating flight hours to Army helicopters." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA350138.

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35

Skoglund, Martin. "Evaluating SLAM algorithms for Autonomous Helicopters." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-12282.

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Navigation with unmanned aerial vehicles (UAVs) requires good knowledge of the current position and other states. A UAV navigation system often uses GPS and inertial sensors in a state estimation solution. If the GPS signal is lost or corrupted state estimation must still be possible and this is where simultaneous localization and mapping (SLAM) provides a solution. SLAM considers the problem of incrementally building a consistent map of a previously unknown environment and simultaneously localize itself within this map, thus a solution does not require position from the GPS receiver.

This thesis presents a visual feature based SLAM solution using a low resolution video camera, a low-cost inertial measurement unit (IMU) and a barometric pressure sensor. State estimation in made with a extended information filter (EIF) where sparseness in the information matrix is enforced with an approximation.

An implementation is evaluated on real flight data and compared to a EKF-SLAM solution. Results show that both solutions provide similar estimates but the EIF is over-confident. The sparse structure is exploited, possibly not fully, making the solution nearly linear in time and storage requirements are linear in the number of features which enables evaluation for a longer period of time.

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36

Kellett, Martin Gerard. "Scheduled multivariable control of battlefield helicopters." Thesis, Cranfield University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333663.

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37

Gavrilets, Vladislav 1975. "Autonomous aerobatic maneuvering of miniature helicopters." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/17609.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2003.
Includes bibliographical references (p. 83-86).
In this thesis, I present an experimentally proven control methodology for the autonomous execution of aerobatic maneuvers with small-scale helicopters, and a low-order dynamic model which adequately describes a miniature helicopter in a wide range of flight conditions, including aerobatics. The control laws consist of steady-state trim trajectory controllers, used prior to, and upon exit from the maneuvers; and a maneuver execution logic inspired by human pilot strategies. In order to test the control laws, a miniature helicopter was outfitted with a custom digital avionics system, and a hardware-in-the-loop simulation was developed. The logic was tested with several aerobatic maneuvers and maneuver sequences, which demonstrated smooth maneuver entry, automatic recovery to a steady-state trim trajectory, and robustness of the trim-trajectory control system toward measurement and modeling errors. Based on these results, I further propose a simplified hybrid model for a helicopter under such closed loop control. The model can be utilized in the development of computationally tractable motion-planning algorithms for agile vehicles.
by Vladislav Gavrilets.
Ph.D.
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38

Dalamagkidis, Konstantinos. "Autonomous vertical autorotation for unmanned helicopters." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0003147.

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39

Cook, Allan B. "Application of neural networks to indirect monitoring of helicopter loads from flight variables." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-12052009-020021/.

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40

Usta, Ebru. "Application of a symmetric total variation diminishing scheme to aerodynamics of rotors." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/13018.

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41

Lewis, William D. "An aeroelastic model structure investigation for a manned real-time rotorcraft simulation." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/13037.

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42

Carstens, Nicol. "Development of a Low-Cost, Low-Weight Flight Control System for an Electrically Powered Model Helicopter." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/993.

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43

Kim, Eulgon. "Optimal helicopter trajectory planning for terrain following flight." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/12932.

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44

Tatossian, Charles A. "Aerodynamic shape optimization via control theory of helicopter rotor blades using a non-linear frequency domain approach." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112586.

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This study presents a discrete adjoint-based aerodynamic optimization algorithm for helicopter rotor blades in hover and forward flight using a Non-Linear Frequency Domain approach. The goal is to introduce a Mach number variation into the Non-Linear Frequency Domain (NLFD) method and implement a novel approach to present a time-varying cost function through a multi-objective adjoint boundary condition. The research presents the complete formulation of the time dependent optimal design problem. The approach is firstly demonstrated for the redesign of a NACA 0007 and a NACA 23012 helicopter rotor blade section in forward flight. A three-dimensional inviscid Aerodynamic Shape Optimization (ASO) algorithm is then employed to validate and redesign the Caradonna and Tung experimental blade. The results in determining the optimum aerodynamic configurations require an objective function which minimizes the inviscid torque coefficient and maintains the desired thrust level at transonic conditions.
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45

Kim, Ho-Sik. "Conceptual design optimization for military helicopter maneuverability and agility." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/11969.

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46

Rye, David Charles. "The longitudinal stability of a tethered rotary-winged aircraft." Thesis, The University of Sydney, 1986. http://hdl.handle.net/2123/18484.

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A linearised mathematical representation of a tethered rctorcraft is developed in order to study the influence of various parameters on the machine’s longitudinal stability. The investigation is concerned principally with a vehicle having two side-by-side contrarotating rotors and a large tailplane. The first part of the thesis consists of a detailed development of the trim equations, and of linearised equations of longitudinal motion which are written in Earth-fixed axes. Aerodynamic derivatives are used to account for the perturbations to rotor and tailplane aerodynamic forces. Dcwnwash lag derivatives are developed using a hcrseshcevortex- plus-wake representation of the flew field of a rotor in forward flight. Because the analysis concentrates on the vehicle's dynamics, a simple quasi-static representation of the single tethering cable is adopted. This approach is adequate provided that the cable mass is a small fraction of the vehicle's mass. When the tether is straight and may be considered inelastic, the Routh-Hurwitz criteria predict that the machine can be made inherently stable in hcver by increasing the thrust tc weight ratio, provided that the cable length dees not exceed a certain small value. The tether must also be attached above the machine's centre of mass tc prevent an aperiodic "pendular" divergence. The same stability criteria show that the machine will be unstable in hcver when the tethering cable is long. When the tether is curved or elastic, simple analytic stability criteria cannot be obtained. Instead, in the second part of the thesis, the influence of various parameters on the vehicle's behaviour is examined by numerically solving particular characteristic equations. The numerical studies show that many vehicle ccnfigurations can be stable in wind, but most are unstable in hcver. The cable attachment point height remains a dominant parameter for hover flight, and in wind. Instability in hover often takes the form of a coupled pitch-translation oscillation similar to that observed in a conventional helicopter. Attaching the tether below the centre of mass can stabilise this oscillation, but results in an aperiodic divergent "pendular" mode. In wind, a tailplane of suitable size will impart asymptotic stability to the system. In strong winds a long tethering cable will be highly curved. The vehicle’s dynamic behaviour is then substantially unrelated to the cable profile. The natural modes shew little dependence on the machine’s geometry, and are strongly influenced by the horizontal tail surface.
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47

Elphick, Jonathan Richard. "Fault tolerance in rotorcraft digital flight control systems." Thesis, University of York, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296389.

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48

Eck, Christoph. "Navigation algorithms with applications to unmanned helicopters /." Zürich : IMRT Press c/o Institut für Mess- und Regeltechnik, ETH Zentrum, 2001. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=14402.

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49

Kummer, Nikolai. "Translational visual servoing control of quadrotor helicopters." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45919.

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Vision based control enables accurate positioning relative to a stationary or moving target of quadrotor helicopters independent of on-board sensor accuracy. The use of vision for helicopter control opens indoor and GPS-denied environments as an area of operation, which currently poses challenges to these systems. This thesis presents a full vision-based quadrotor helicopter controller for tracking a stationary or slow-moving target. The full controller used three control loops. The outer control loop converts an image feature error into UAV velocity commands. The quadrotor is a nonlinear system that has highly coupled position and attitude dynamics. The second loop performed a feedback linearization on these dynamics and translated the desired velocity into attitude commands. The inner loop was an on-board attitude and altitude controller, which was part of the ARDrone system and which was analyzed via frequency domain system identification for its dynamics. A linear quadratic Gaussian (LQG) controller, consisting of a Kalman filter for state estimation and a linear quadratic regulator was used to control the linearized system. The visual servoing control scheme was image based which convergences towards the desired configuration independent of on-board sensor accuracy and in the presence of camera calibration errors. The visual servoing features, used to control the translational degrees of freedom, sphere based on the virtual sphere approach, which uses two points in 3D space to create a virtual sphere. Control of the helicopter in the x and y direction was linked to the center location of the virtual sphere and distance to the target was controlled by the virtual sphere radius. The target features were two points, detected by colour and shape based detection methods. Adaboost.MRT, a boosting method for multivariate regression is proposed as part of this thesis. Adaboost.MRT is based on Adaboost.RT and extends the original to multivariate regression, improves boosting’s noise sensitivity, and improves the singularity in the misclassification function. A variance-scaled misclassification function is proposed and the threshold parameter is expanded to accommodate vector output. The proposed method is tested on eight datasets and displays a similar or better accuracy than the original Adaboost.RT or the base learning algorithm.
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50

Orihuela, Swartling Johanna. "Circumnavigation with a group of quadrotor helicopters." Thesis, KTH, Reglerteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-143182.

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The primary goal of this thesis has been to implement Collective Circumnavigation. Given a group of unmanned aerial vehicles (UAVs) and the position of a target, the UAVs should approach the target and start circulating around it at a desired distance while forming a regular polygon. In this project quadrotor helicopters were used to conduct experiments and so a secondary goal was to study and implement control of quadrotors. The overall control of a quadrotor can be divided into three layers; attitude control, position control and path planning. The attitude of a quadrotor describes the orientation, i.e. how much the quadrotor is tilted, with respect to a referance frame. The attitude controller represents the innermost layer of the controller since all translational motions are achieved by tilting the quadrotor. A position controller represents the middle layer and is used to determine how much the quadrotor needs to tilt to get to a certain desired position. The outermost layer is the path planner which decides the trajectory of the quadrotor. The path planner is in this project given by the Circumnavigation algorithm. For both attitude and position control, the chosen controllers focus on the orientation of the thrust vector. The thrust vector points straight up from the center of mass of the quadrotor and is the sum of the thrust forces caused by the four rotors. The position controller calculates the desired direction of the thrust vector while the attitude controller aligns the real thrust vector with the desired one. Both controllers uses quaternions to describe the orientation of the thrust vector and to prioritize the alignment. Simulation results show that it was possible to merge the chosen controllers and experimental results show the feasibility of Collective Circumnavigation.
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