Morphing aircraft combine both radical and subtle wing shape changes to improve vehicle performance relative to a rigid airframe. An aircraft wind tunnel model with considerable wing-shape freedom can serve as a tool in learning to model, control, and fully exploit the potential of such vehicles. This work describes the design, development, and initial analysis of a wind tunnel model that combines large and small wing shape variations for fundamental research in modeling and control of morphing air vehicles. The vehicle is designed for five primary purposes: quasi-steady aerodynamic modeling of an aircraft with large planform changes, optimization studies in achieving efficient flight configurations, transient aerodynamic modeling of high-rate planform changes, evaluating planform maneuvering as an control effector, and gimbaled flight control simulation of a morphing aircraft. The knowledge gained from the wind tunnel evaluations will be used to develop general stabilization and optimal control strategies that can be applied to other vehicles with large scale planform changes and morphing flight models. After a brief background on the development of the Morphing Aircraft Program, and previous research ventures, the first phase vehicle development is described. The vehicle function, subsystems, and control are all presented in addition to the results of first phase wind tunnel testing. Deficiencies in the phase one design motivated the phase two development which has led to the current vehicle model: MORPHEUS. The evolution towards the MORPHEUS configuration is presented in detail along with an elementary strength analysis. The new embedded control implementation to permit a rate controllable planform is included. A preliminary aerodynamic analysis is presented to contrast MORPHEUS against the phase one design and an industry morphing concept. In particular, it is shown how the redesigned model has enhanced performance characteristics and the additional degrees of freedom enable greater flexibility in optimizing a configuration, especially with respect to trim characteristics. An expansion of traditional analysis techniques is applied to derive a new optimal twist algorithm for the MORPHEUS model at each planform configuration. The analysis concludes with a hybrid continuous modeling method that combines first-order computational aerodynamic modeling with classic stability expressions and DATCOM enhancements. The elementary aerodynamic coefficients are computed over the range of possible planform configurations and combined with the optimal twist results for preliminary trim analysis. This work precedes phase two wind tunnel testing and transient modeling. Future work involves expansion into the five purposes detailed for the MORPHEUS model. / Master of Science

The application of smart materials to control the flight dynamics of a Micro Air Vehicle (MAV) has numerous benefits over traditional servomechanisms. Under study is wing morphing achieved through the use of piezoelectric Macro Fiber Composites (MFCs). These devices exhibit low power draw but excellent bandwidth characteristics. This thesis provides a background in the 2D analytical and computer modeling tools and methods needed to design and characterize an MFC-actuated airfoil. A composite airfoil is designed with embedded MFCs in a bimorph configuration. The deflection capabilities under actuation are predicted with the commercial finite element package NX Nastran. Placement of the piezoelectric actuator is studied for optimal effectiveness. A thermal analogy is used to represent piezoelectric strain. Lift and drag coefficients in low Reynolds number flow are explored with XFOIL. Predictions are made on static aeroelastic effects. The thin, cambered Generic Micro Aerial Vehicle (GenMAV) airfoil is fabricated with a bimorph actuator. Experimental data are taken with and without aerodynamic loading to validate the computer model. This is accomplished with in-house 2D wind tunnel testing. / Master of Science

[Truncated abstract] Image transition effects are commonly used on television and human computer interfaces. The transition between images creates a perception of continuity which has aesthetic value in special effects and practical value in visualisation. The work in this thesis demonstrates that better image transition effects are obtained by incorporating properties of projective geometry into image transition algorithms. Current state-of-the-art techniques can be classified into two main categories namely shape interpolation and warp generation. Many shape interpolation algorithms aim to preserve rigidity but none preserve it with perspective effects. Most warp generation techniques focus on smoothness and lack the rigidity of perspective mapping. The affine transformation, a commonly used mapping between triangular patches, is rigid but not able to model perspective effects. Image transition techniques from the view interpolation community are effective in creating transitions with the correct perspective effect, however, those techniques usually require more feature points and algorithms of higher complexity. The motivation of this thesis is to enable different views of a planar surface to be interpolated with an appropriate perspective effect. The projective geometric relationship which produces the perspective effect can be specified by two quadrilaterals. This problem is equivalent to finding a perspectively appropriate interpolation for projective transformation matrices. I present two algorithms that enable smooth perspective transition between planar surfaces. The algorithms only require four point correspondences on two input images. ...The second algorithm generates transitions between shapes that lie on the same plane which exhibits a strong perspective effect. It recovers the perspective transformation which produces the perspective effect and constrains the transition so that the in-between shapes also lie on the same plane. For general image pairs with multiple quadrilateral patches, I present a novel algorithm that is transitionally symmetrical and exhibits good rigidity. The use of quadrilaterals, rather than triangles, allows an image to be represented by a small number of primitives. This algorithm uses a closed form force equilibrium scheme to correct the misalignment of the multiple transitional quadrilaterals. I also present an application for my quadrilateral interpolation algorithm in Seitz and Dyer's view morphing technique. This application automates and improves the calculation of the reprojection homography in the postwarping stage of their technique. Finally I unify different image transition research areas into a common framework, this enables analysis and comparison of the techniques and the quality of their results. I highlight that quantitative measures can greatly facilitate the comparisons among different techniques and present a quantitative measure based on epipolar geometry. This novel quantitative measure enables the quality of transitions between images of a scene from different viewpoints to be quantified by its estimated camera path.

Thesis (MSc (Mathematical Sciences. Applied Mathematics))--University of Stellenbosch, 2007. / Image morphing is a popular technique used to create spectacular visual effects, by gradually transforming one image into another. This thesis explains what exactly is meant by the terms “image morphing” / “warping”, where it is used and how it is done. A few existing morphing techniques are described and finally an implementation using Delaunay triangulation and texture mapping is presented.

No description available.

A triangulação de Delaunay de um conjunto de pontos é uma importante entidade geométrica cujas aplicações abrangem diversas áreas da ciência. Triangulações regulares, que podem ser vistas como uma generalização da triangulação de Delaunay, onde pesos são associados aos vértices, também têm sido aplicadas em diversos problemas como reconstrução a partir de nuvens de pontos [5], geração de malha [12], modelagem molecular [7] e muitos outros. Apesar de ser muito utilizada, a fundamentação teórica referente à triangulação regular ainda não está tão desenvolvida quanto para triangulação de Delaunay. Por exemplo, pouco se sabe a respeito da dinâmica de uma triangulação regular [22] quando os pesos associados aos vértices mudam. Este trabalho tem como objetivo principal desenvolver um arcabouço teórico e computacional que permita representar uma triangulação qualquer como uma triangulação regular. Para isso, um estudo da dinâmica das operações de flip frente à variação de pesos nos vértices deve ser realizado. Este estudo tem como base o mapeamento da triangulação em um politopo que define os possíveis pesos para os vértices. Tal politopo pode ser obtido por meio de um sistema de inequações que gera um problema de programação linear cuja solução fornece os pesos adequados. A transformação de uma triangulação qualquer em triangulação regular permite o desenvolvimento de novas técnicas de morphing entre malhas e algoritmos para modelar níveis de detalhe, sendo este mais um objetivo deste trabalho / Delaunay triangulation of a set of points is an important geometrical entity whose applications encompass a range of scientfic fields. Regular triangulations, which can be seen as a generalization of Delaunay triangulation where weights are assigned to vertices, have also been widely employed in several problems, as for example mesh reconstruction from point clouds [5], mesh generation [12] and molecular modelling [7]. In spite of their applicability, the theoretical background of regular triangulations is not so developed as the theory of Delaunay triangulation. For example, the dynamic of regular triangulation is not completely known when the vertices weights change [22]. This work aims at developing a computational and theoretical framework that allow to represent a given triangulation as a regular triangulation. In this context, an investigation into the dynamic of edge ip operations regarding changes in the vertices weight must be accomplished. This investigation is based on mapping the triangulation in a polytope that defines the space of vertices weights. Such polytope can be built from an inequation system that can be associate to a linear program problem whose solution supplies the appropriated weights. By representing a triangulation as a regular triangulation one can conceive a new mesh morphing scheme and level of detail algorithm, being this another goal of this work

Os recentes desenvolvimentos na tecnologia de sistema aeronáutico de geometria variável têm sido motivados principalmente pela necessidade de melhorar o desempenho de aeronaves. O conceito de Morphing Aircraft, por meio da variação da linha de arqueamento, representa uma alternativa para sistemas aeronáuticos mais eficientes. No entanto, para aeronaves de alto desempenho, projetos com estes novos conceitos podem gerar reações aeroelásticas adversas, o que representa uma questão importante e pode vir a limitar esses novos projetos. A compreensão adequada do comportamento aeroelástico devido à variação da linha de arqueamento, particularmente em regimes transônico, compreende uma questão importante. Este trabalho consiste num estudo preliminar das consequências aeroelásticas de um sistema aeronáutico de geometria variável. O objetivo desse trabalho é explorar as repostas aeroelásticas transônicas de um aerofólio com arqueamento variável no tempo. A metodologia para análise aeroelástica é baseada num modelo de seção típica. A integração no tempo do sistema aeroelástico é obtida pelo método de Runge-Kutta de quarta ordem. A representação do escoamento transônico não estacionário foi computada por um código CFD em um contexto de malhas não estruturadas com uma formulação dada pelas equações de Euler-2D. Esses resultados preliminares podem fornecer aos projetistas informações importantes sobre as respostas aeroelásticas de um sistema aeronáutico com variação da linha de arqueamento, permitindo estabelecer um quadro adequado para futuras investigações de controle aeroelástico de sistema aeronáutico de geometria variável. / Recent developments on aircraft variable geometry technologies have been mainly motivated by the need for improving the flight performance. The morphing wing concept, by means of variable camber, represents an alternative towards more efficient lifting surfaces. However, for higher performance aircraft, this technology may lead to designs that create unsteady loads, which may result in adverse aeroelastic responses, which represents an important and limiting issue. Proper understanding of the aeroelastic behavior, particularly in transonic flight regimes, due to variations in camber comprises an important matter. This work is a primary study of aeroelastic consequences of an real-time adaptive aircraft. The objective of this work is to investigate prescribed variations to airfoil camberline and their influence to the aeroelastic response in transonic flight regime. The methodology is based on computational simulations of typical section with unsteady transonic aerodynamics solved with a Computational Fluid Dynamics (CFD) code. The time integration of the aeroelastic system is obtained by Runge-Kutta fourth order. The unsteady transonic flow was computed by a CFD code based on the 2D-Euler equations with unstructured mesh. Prescribed camber variation of a symmetrical airfoil is transferred to the CFD mesh, and aeroelastic responses and loading is assessed. These preliminary results may provide the designers valuable information on the interaction between changes in camber during airfoil aeroelastic reactions, allowing establishing an adequate framework for further aeroelastic control investigations of morphing wings.

A triangulação de Delaunay de um conjunto de pontos é uma importante entidade geométrica cujas aplicações abrangem diversas áreas da ciência. Triangulações regulares, que podem ser vistas como uma generalização da triangulação de Delaunay, onde pesos são associados aos vértices, também têm sido aplicadas em diversos problemas como reconstrução a partir de nuvens de pontos [5], geração de malha [12], modelagem molecular [7] e muitos outros. Apesar de ser muito utilizada, a fundamentação teórica referente à triangulação regular ainda não está tão desenvolvida quanto para triangulação de Delaunay. Por exemplo, pouco se sabe a respeito da dinâmica de uma triangulação regular [22] quando os pesos associados aos vértices mudam. Este trabalho tem como objetivo principal desenvolver um arcabouço teórico e computacional que permita representar uma triangulação qualquer como uma triangulação regular. Para isso, um estudo da dinâmica das operações de flip frente à variação de pesos nos vértices deve ser realizado. Este estudo tem como base o mapeamento da triangulação em um politopo que define os possíveis pesos para os vértices. Tal politopo pode ser obtido por meio de um sistema de inequações que gera um problema de programação linear cuja solução fornece os pesos adequados. A transformação de uma triangulação qualquer em triangulação regular permite o desenvolvimento de novas técnicas de morphing entre malhas e algoritmos para modelar níveis de detalhe, sendo este mais um objetivo deste trabalho / Delaunay triangulation of a set of points is an important geometrical entity whose applications encompass a range of scientfic fields. Regular triangulations, which can be seen as a generalization of Delaunay triangulation where weights are assigned to vertices, have also been widely employed in several problems, as for example mesh reconstruction from point clouds [5], mesh generation [12] and molecular modelling [7]. In spite of their applicability, the theoretical background of regular triangulations is not so developed as the theory of Delaunay triangulation. For example, the dynamic of regular triangulation is not completely known when the vertices weights change [22]. This work aims at developing a computational and theoretical framework that allow to represent a given triangulation as a regular triangulation. In this context, an investigation into the dynamic of edge ip operations regarding changes in the vertices weight must be accomplished. This investigation is based on mapping the triangulation in a polytope that defines the space of vertices weights. Such polytope can be built from an inequation system that can be associate to a linear program problem whose solution supplies the appropriated weights. By representing a triangulation as a regular triangulation one can conceive a new mesh morphing scheme and level of detail algorithm, being this another goal of this work

Morphing air vehicles enable more efficient and capable multi-role aircraft by adapting their shape to reach an ideal configuration in an ever-changing environment. Morphing capability is envisioned to have a profound impact on the future of the aerospace industry, and a reconfigurable wing is a significant element of a morphing aircraft. This thesis develops two tools for analyzing wing configurations with multiple geometric degrees-of-freedom: the structural tool and the aerodynamic and structural interaction tool. Linear Space Frame Finite Element Analysis with Euler-Bernoulli beam theory is used to develop the structural analysis morphing tool for modeling a given wing structure with variable geometric parameters including wing span, aspect ratio, sweep angle, dihedral angle, chord length, thickness, incidence angle, and twist angle. The structural tool is validated with linear Euler-Bernoulli beam models using a commercial finite element software program, and the tool is shown to match within 1% compared to all test cases. The verification of the structural tool uses linear and nonlinear Timoshenko beam models, 3D brick element wing models at various sweep angles, and a complex wing structural model of an existing aircraft. The beam model verification demonstrated the tool matches the Timoshenko models within 3%, but the comparisons to complex wing models show the limitations of modeling a wing structure using beam elements. The aerodynamic and structural interaction tool is developed to integrate a constant strength source doublet panel method aerodynamic tool, developed externally to this work, with the structural tool. The load results provided by the aerodynamic tool are used as inputs to the structural tool, giving a quasi-static aeroelastically deflected wing shape. An iterative version of the interaction tool uses the deflected wing shape results from the structural tool as new inputs for the aerodynamic tool in order to investigate the geometric convergence of an aeroelastically deflected wing shape. The findings presented in this thesis show that geometric convergence of the deflected wing shape is not attained using the chosen iterative method, but other potential methods are proposed for future work. The tools presented in the thesis are capable of modeling a wide range of wing configurations, and they may ultimately be utilized by Machine Learning algorithms to learn the ideal wing configuration for given flight conditions and develop control laws for a flyable morphing air vehicle.

La Dynamique de la Persistance Identitaire se veut, à travers l'autoportrait plastique, une analyse des notions du moi et du surmoi. L'autoportrait soulève pour la majorité des artistes, des plus anciens aux plus novateurs, la question de l'identité à travers l'apparence, le caractère, mais aussi des origines sociales et culturelles et son exacerbation amène à un narcissisme qui fut le moteur de l'activité de nombreux maîtres parmi les plus illustres. Se remémorer certaines périodes de la vie, des souvenirs heureux ou malheureux de situations vécues, conduit à l'introspection, où le temps est une notion majeure artistique et nécessaire à la structuration psychologique d'un individu. De nombreux artistes se sont penchés sur leur image en employant de nombreuses techniques plastiques traditionnelles et, depuis peu, expérimentales (expériences tridimensionnelles). Ces représentations, à l'aide des nouveaux outils informatiques accessibles à tous, sont désormais modifiables à volonté, apportant un choix illimité d'altérations réversibles en mode uniquement virtuel. Dans un travail initial (Evolution Identitaire) ce dessein interroge l'autoportrait de l'auteur à l'aide de dessins unicolores éclairés de rehauts de blancs ou chaque visage apparaît trait par trait pour constituer l'individu. La Dynamique de la Persistance Identitaire remet en question ces trente et un visages représentés le plus objectivement possible pour dévier de l'image réelle à l'image rêvée, par la technique du Makeover, très utilisé sur internet et donnant ainsi une possibilité de reconquête de l'identité, à la recherche d'une esthétique optimisée, adaptée au choix de l'artiste: deux cent dix-sept dessins, toutes réalisations confondues, sont ainsi conçus. Cet ensemble est diffusé à travers une exposition et une vidéo et il est adaptable à plusieurs espaces sous trois formes complémentaires :une double frise chronologique en parallèle d'autoportraits format A4 sur un papier légèrement teinté où sont confrontées représentations objectives et subjectives des formes suivant les critères des lois de la Gestalt. une vidéo projection ou les visages se dévoilent progressivement, donnant ainsi naissance à une technique dite "dessin évolutif', proche de l'animation, et donnant vie à l'individu avec le morphing en étape ultime qui dévoile avec fluidité un nouveau visage rectifié selon les désirs de l'auteur, une longue frise chronologique format A2 blanc où l'image vécue est couplée et confronté à l'image idéalisée, sur une même représentation, par deux couleurs différentes pour signifier les corrections accomplies. Cette recherche devrait être complétée, dans l'avenir, toujours avec pour moteur la recherche de réalisations d'autoportraits tridimensionnels, à l'aide de technologies pointues, telles anamorphoses et imprimante 3D. / Dynamics of identity Persistence wants, through the plastic self-portrait, an analysis of the concepts of ego and superego. Self Portrait raises for the majority of artists, from the oldest to the most innovative, the question of identity through the appearance, character, but also social and cultural origins and exacerbation leads to a narcissism that was the engine the activity of man y of Art masters. Remember certain periods of life, happy or unhappy memories of life situations, leads to introspection, where time is a necessary artistic and psychological structuring an individual major concept. Many artists have focused on their image using many traditional engineering plastics and, more recently, experimental (three-dimensional experiments). These representations using new tools accessible to all are now modified at will, bringing unlimited choice reversible alterations only virtual mode. In initial work (Identity Evolution) this design questions the portrait of the author with one colored drawings illuminated highlights of each face appears white or line by line to form the individual. Dynamics of identity Persistence puts into these thirty questions and faces presented as objectively as possible to deviate from the actual image to the perfect picture, the technique Makeover, widely used on the Internet and giving an opportunity to reconquer identity, the search for an aesthetic optimized, adapted to the choice of the artist: two hundred and seventeen drawings, ail outputs combined, are well designed. This package is distributed through an exhibition and a video that is adaptable to many spaces in three complementary ways:-A double timeline of self-portraits in parallel on A4 paper with a lightly tinted face objective and subjective representations of forms depending on the requirements of Gestalt's laws. -A video projection where faces are gradually revealed, giving rise to " evolutionary drawing " , close to the animation technique, and giving life to the individual with the morphing ultimate step reveals a new face smoothly corrected according to the wishes of the author. -A long white frieze chronological format A2 where the image is coupled lived and confronted with the idealized image, on the same representation by two different colors to signify the completed corrections. This research should be completed in the future, always with engine research achievements of three-dimensional self-portraits, with pointed and such anamorphic 30 printer technologies.