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Military innovation and the helicopter : a comparison of development in the United States Army and Marine Corps, 1945-1953 /Horn, Carl John, January 2000 (has links)
Thesis (M.A.)--Ohio State University, 2000. / Cover title. Includes vita. Includes abstract. Includes bibliographical references (leaves 82-96). Available online via OhioLINK's ETD Center.
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Strain measurement of composite materials using fibre optic sensors /Furlong, Peter Andrew Caskey. January 1900 (has links)
Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 166-174). Also available in electronic format on the Internet.
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CAS, interdiction, and attack helicoptersGroenke, Andrew S. January 2005 (has links) (PDF)
Thesis (M.A.)--Naval Postgraduate School, 2005. / Title from title screen (viewed Jan. 31, 2006). "June 2005." Includes bibliographical references (p. 63-67). Also issued in paper format.
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Military innovation and the helicopter : a comparison of development in the United States Army and Marine Corps, 1945-1965 /Horn, Carl John, January 2003 (has links)
Thesis (Ph. D.) -- Ohio State University, 2003. / Includes vita. Includes abstract. Includes bibliographical references (leaves 341-356). Also available via Internet from the Ohio State Library and Information Network electronic theses public database. Adobe Acrobat reader required. Address as of 1/06/2006: http://www.ohiolink.edu/etd/send-pdf.cgi?osu1054563128.
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CAS, interdiction, and attack helicopters /Groenke, Andrew S. January 2005 (has links) (PDF)
Thesis (M.A. in National Security Affairs)--Naval Postgraduate School, June 2005. / Thesis Advisor(s): Daniel Moran. Includes bibliographical references (p. 63-67). Also available online.
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Electronic warfare self-protection of battlefield helicopters : a holistic view /Heikell, Johnny. Unknown Date (has links) (PDF)
Thesis (Ph. D.)--Helsinki University of Technology, Applied Electronics Laboratory, 20-05. / Also available online.
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PID έλεγχος για QuadrotorΘάνου, Μιχαήλ 04 October 2011 (has links)
Αντικείμενο της εργασίας είναι ο έλεγχος του προσανατολισμού ελικοπτέρου Quadrotor με χρήση ελεγκτή PID. Το ελικόπτερο Quadrotor είναι ένα μη γραμμικό, ασταθές, υποενεργοποιούμενο σύστημα. Για αυτούς τους λόγους, ο έλεγχός του παρουσιάζει σοβαρά προβλήματα. Ο ελεγκτής PID αρχικά εφαρμόζεται στο γραμμικοποιημένο μοντέλο του συστήματος, και εν συνεχεία διακριτοποιείται και εξετάζεται στο πλήρες μη γραμμικό μοντέλο του Quadrotor. Ιδιαίτερο βάρος δίνεται στη ρύθμιση του ελεγκτή PID. Αφού παρουσιαστούν οι κυριότερες μέθοδοι ρύθμισης ενός τέτοιου ελεγκτή, επιλέγεται η μέθοδος Extremum Seeking, μία επαναληπτική μέθοδος που βελτιστοποιεί τον PID ώστε να ελαχιστοποιείται τοπικά μια συνάρτηση κόστους. Σημαντικό πλεονέκτημα αυτής της μεθόδου αποτελεί το γεγονός ότι μπορεί να εφαρμοστεί κατ' ευθείαν στο μη γραμμικό μοντέλο του συστήματος βελτιστοποιώντας περαιτέρω τον ελεγκτή. Στη συνέχεια ο ελεγκτής PID εξετάζεται σε ένα πραγματικό ελικόπτερο που κατασκευάστηκε στο εργαστήριο. Στο πειραματικό αυτό σύστημα, η υλοποίηση του PID γίνεται σε έναν ηλεκτρονικό υπολογιστή, με τη βοήθεια του προγράμματος Labview ενώ η επικοινωνία ανάμεσα στον υπολογιστή και στο ελικόπτερο επιτυγχάνεται με τη βοήθεια σειριακής θύρας RS232. Μετά τη διεξαγωγή των πειραμάτων και την αξιολόγηση της απόδοσης του ελεγκτή PID, αναφέρονται τα γενικότερα συμπεράσματα της εργασίας, καθώς και προτάσεις για περαιτέρω έρευνα. / This thesis focuses on attitude control of a quadrotor helicopter with PID technique. Quadrotor is a non linear, unstable, underactuated system, so the controller design is a very challenging task. Initially the PID controller is applied to the linearized model of the helicopter, and then to the discretized one, because the controller is later implemented on a personal computer. Then we describe some PID tuning techniques that are often used in practice. In this thesis we use Extemum Seeking which is an iterative, optimization method for the PID tuning that can be used in either linear or non linear models. So Extremum Seeking can be applied to the full non linear model of the quadrotor to further improve the PID parameters. Finally the PID controller is applied to a real Quadrotor helicopter. The controller is implemented on Labview while the communication between the PC and the helicopter is achieved with two RS232 links.
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Design of a DDP controller for autonomous autorotative landing of RW UAV following engine failureMatlala, Puseletso January 2016 (has links)
A dissertation submitted to the Faculty of Engineering and the Built Environment,
University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements
for the degree of Master of Science in Engineering.
Johannesburg, April 2016 / A Rotary Wing Unmanned Aerial Vehicle (RW UAV) as a platform and its payload
consisting of sophisticated sensors would be costly items. Hence, a RW UAV in the
500 kg class designed to fulfil a number of missions would represent a considerable
capital outlay for any customer. Therefore, in the event of an engine failure, a means
should be provided to get the craft safely back on the ground without incurring
damage or causing danger to the surrounding area. The aim of the study was
to design a controller for autorotative landing of a RW UAV in the event of engine
failure. In order to design a controller for autorotative landing, an acceleration model
was used obtained from a study by Stanford University. FLTSIM helicopter flight
simulation package yielded necessary RW UAV response data for the autorotation
regimes. The response data was utilized in identifying the unknown parameters
in the acceleration model. A Differential Dynamic Programming (DDP) control
algorithm was designed to compute the main and tail rotor collective pitch and the
longitudinal and lateral cyclic pitch control inputs to safely land the craft. The
results obtained were compared to the FLTSIM flight simulation response data.
It was noted that the mathematical model could not accurately model the pitch
dynamics. The main rotor dynamics were modelled satisfactorily and which are
important in autorotation because without power from the engine, the energy in
main rotor is critical in a successful execution of an autorotative landing. Stanford
University designed a controller for RC helicopter, XCell Tempest, which was deemed
successful. However, the DDP controller was designed for autonomous autorotative
landing of RW UAV weighing 560 kg, following engine failure. The DDP controller
has the ability to control the RW UAV in an autorotation landing but the study
should be taken further to improve certain aspects such as the pitch dynamics and
which can possibly be achieved through online parameter estimation. / MT 2017
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Sampling-based Path Planning for an Autonomous HelicopterPettersson, Per Olof January 2006 (has links)
Many of the applications that have been proposed for future small unmanned aerial vehicles (UAVs) are at low altitude in areas with many obstacles. A vital component for successful navigation in such environments is a path planner that can find collision free paths for the UAV. Two popular path planning algorithms are the probabilistic roadmap algorithm (PRM) and the rapidly-exploring random tree algorithm (RRT). Adaptations of these algorithms to an unmanned autonomous helicopter are presented in this thesis, together with a number of extensions for handling constraints at different stages of the planning process. The result of this work is twofold: First, the described planners and extensions have been implemented and integrated into the software architecture of a UAV. A number of flight tests with these algorithms have been performed on a physical helicopter and the results from some of them are presented in this thesis. Second, an empirical study has been conducted, comparing the performance of the different algorithms and extensions in this planning domain. It is shown that with the environment known in advance, the PRM algorithm generally performs better than the RRT algorithm due to its precompiled roadmaps, but that the latter is also usable as long as the environment is not too complex. The study also shows that simple geometric constraints can be added in the runtime phase of the PRM algorithm, without a big impact on performance. It is also shown that postponing the motion constraints to the runtime phase can improve the performance of the planner in some cases. / <p>Report code: LiU–Tek–Lic–2006:10.</p>
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Military innovation and the helicopter: a comparison of development in the United States army and marine corps, 1945-1965Horn, Carl J., III January 2004 (has links)
No description available.
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