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Tesi sul tema "Kinematic"
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1
Zaplana, Agut Isiah. "Solving robotic kinematic problems : singularities and inverse kinematics." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/667496.
Testo completoAbstract (sommario):
Kinematics is a branch of classical mechanics that describes the motion of points, bodies, and systems of bodies without considering the forces that cause such motion. For serial robot manipulators, kinematics consists of describing the open chain geometry as well as the position, velocity and/or acceleration of each one of its components. Rigid serial robot manipulators
are designed as a sequence of rigid bodies, called links, connected by motor-actuated pairs, called joints, that provide relative motion between consecutive links. Two kinematic problems of special relevance for serial robots are:
- Singularities: are the configurations where the robot loses at least one degree of freedom (DOF). This is equivalent to:
(a) The robot cannot translate or rotate its end-effector in at least one direction.
(b) Unbounded joint velocities are required to generate finite linear and angular velocities.
Either if it is real-time teleoperation or off-line path planning, singularities must be addressed to make the robot exhibit a good performance for a given task. The objective is not only to identify the singularities and their associated singular directions but to design strategies to avoid or handle them.
- Inverse kinematic problem: Given a particular position and orientation of the end-effector, also known as the end-effector pose, the inverse kinematics consists of finding the configurations that provide such desired pose. The importance of the inverse kinematics relies on its role in the programming and control of serial robots. Besides, since for each given pose the inverse kinematics has up to sixteen different solutions, the objective is to find a closed-form method for solving this problem, since closed-form methods allow to obtain all the solutions in a compact form.
The main goal of the Ph.D. dissertation is to contribute to the solution of both problems. In particular, with respect to the singularity problem, a novel scheme for the identification of the singularities and their associated singular directions is introduced. Moreover, geometric algebra is used to simplify such identification and to provide a distance function in the configuration space of the robot that allows the definition of algorithms for avoiding them.
With respect to the inverse kinematics, redundant robots are reduced to non-redundant ones by selecting a set of joints, denoted redundant joints, and by parameterizing their joint variables. This selection is made through a workspace analysis which also provides an upper bound for the number of different closed-form solutions. Once these joints have been identified, several
closed-form methods developed for non-redundant manipulators can be applied to obtain the analytical expressions of all the solutions. One of these methods is a novel strategy developed using again the conformal model of the spatial geometric algebra.
To sum up, the Ph.D dissertation provides a rigorous analysis of the two above-mentioned kinematic problems as well as novel strategies for solving them. To illustrate the different results introduced in the Ph.D. memory, examples are given at the end of each of its chapters.<br>La cinemática es una rama de la mecánica clásica que describe el movimiento de puntos, cuerpos y sistemas de cuerpos sin considerar las fuerzas que causan dicho movimiento. Para un robot manipulador serie, la cinemática consiste en la descripción de su geometría, su posición, velocidad y/o aceleración. Los robots manipuladores serie están diseñados como una secuencia de elementos estructurales rígidos, llamados eslabones, conectados entres si por articulaciones actuadas, que permiten el movimiento relativo entre pares de eslabones consecutivos. Dos problemas cinemáticos de especial relevancia para robots serie son: - Singularidades: son aquellas configuraciones donde el robot pierde al menos un grado de libertad (GDL). Esto equivale a: (a) El robot no puede trasladar ni rotar su elemento terminal en al menos una dirección. (b) Se requieren velocidades articulares no acotadas para generar velocidades lineales y angulares finitas. Ya sea en un sistema teleoperado en tiempo real o planificando una trayectoria, las singularidades deben manejarse para que el robot muestre un rendimiento óptimo mientras realiza una tarea. El objetivo no es solo identificar las singularidades y sus direcciones singulares asociadas, sino diseñar estrategias para evitarlas o manejarlas. - Problema de la cinemática inversa: dada una posición y orientación del elemento terminal (también conocida como la pose del elemento terminal), la cinemática inversa consiste en obtener las configuraciones asociadas a dicha pose. La importancia de la cinemática inversa se basa en el papel que juega en la programación y el control de robots serie. Además, dado que para cada pose la cinemática inversa tiene hasta dieciséis soluciones diferentes, el objetivo es encontrar un método cerrado para resolver este problema, ya que los métodos cerrados permiten obtener todas las soluciones en una forma compacta. El objetivo principal de la tesis doctoral es contribuir a la solución de ambos problemas. En particular, con respecto al problema de las singularidades, se presenta un nuevo método para su identificación basado en el álgebra geométrica. Además, el álgebra geométrica permite definir una distancia en el espacio de configuraciones del robot que permite la definición de distintos algoritmos para evitar las configuraciones singulares. Con respecto a la cinemática inversa, los robots redundantes se reducen a robots no-redundantes mediante la selección de un conjunto de articulaciones, las articulaciones redundantes, para después parametrizar sus variables articulares. Esta selección se realiza a través de un análisis de espacio de trabajo que también proporciona un límite superior para el número de diferentes soluciones en forma cerrada. Una vez las articulaciones redundantes han sido identificadas, varios métodos en forma cerrada desarrollados para robots no-redundantes pueden aplicarse a fin de obtener las expresiones analíticas de todas las soluciones. Uno de dichos métodos es una nueva estrategia desarrollada usando el modelo conforme del álgebra geométrica tridimensional. En resumen, la tesis doctoral proporciona un análisis riguroso de los dos problemas cinemáticos mencionados anteriormente, así como nuevas estrategias para resolverlos. Para ilustrar los diferentes resultados presentados en la tesis, la memoria contiene varios ejemplos al final de cada uno de sus capítulos.
2
Šimková, Kristýna. "Návrh SW pro řízení delta robotu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-400926.
Testo completoAbstract (sommario):
This thesis deals with software creation for delt robot in TwinCAT 3 program. First part describes the general characteristics of a delta robot. Next part deals with hardware and PLC coding in TwinCAT 3 and the final part discusses the creation of an application.
3
Kozubík, Jiří. "Experimentální robotizované pracoviště s delta-robotem." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229633.
Testo completoAbstract (sommario):
This diploma thesis was written within Czech-German study programme Production systems (VUT v Brně & TU Chemnitz). This thesis is divided into four main parts. In the first part is brought out the introduction to design of robotic cells. Following part is concentrated on analysis of present state in area of machines with parallel kinematics. The penultimate part, on which is focused the main attention, is dedicated to kinematic analysis of delta-robot. Closing part of this Thesis presents the study of experimental robotized workplace with integrated delta-robot.
4
Fabricius, Maximilian Hieronymus. "Kinematics across bulge types a longslit kinematic survey and dedicated instrumentation." Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-144409.
Testo completo
5
Summerfield, Philip John. "Kinematic GPS surveying." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254471.
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Cuffaro, Marco. "Plate Kinematic Models." Doctoral thesis, La Sapienza, 2007. http://hdl.handle.net/11573/917380.
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Centea, Dan Elbestawi Mohamed A. A. "Design, kinematics and dynamics of a machine tool based on parallel kinematic structure." *McMaster only, 2004.
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8
Whittingham, Ben. "Applications of the kinematic modelling of a parallel kinematic mechanism machine tool." Thesis, University of Nottingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272714.
Testo completo
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Liu, Zheng 1962. "Kinematic optimization of linkages." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39742.
Testo completoAbstract (sommario):
Presented in this thesis are novel methodologies for the analysis and optimization of planar, spherical, and spatial linkages associated with the problems of function generation, path generation, and rigid-body guidance. An up-to-date literature survey in the area of mechanism optimization is also provided in the thesis.<br>Both the input-output (I/O) equation and the I/O curve are employed in the input-output analysis of four-bar linkages. Based on these, the properties of a special class of linkage, the constant-branch linkage, as well as its engineering application are discussed. Two schemes are developed for the optimization of function-generating linkages, namely, a constrained least-square procedure using slack variables and an unconstrained method based on I/O curve planning. The issue of data-conditioning is also discussed so that singularities can be avoided in the optimization procedure.<br>With the help of linkage coordinate systems defined in this thesis, equations governing the coupler-link motion are derived for both path generation and rigid-body guidance. In the optimization of path-generating and rigid-body guiding linkages, a two-loop scheme based on a constrained least-square procedure is first proposed. Then, as an extension to I/O curve planning in function generation, a method resorting to input-output-coupler (I/O-C) curve planning is developed for path generation and rigid-body guidance. Using unconstrained approaches, this method simplifies the optimization procedure to a great extent.
10
Walsh, David M. A. "Kinematic GPS ambiguity resolution." Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239858.
Testo completo
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Evans, Andrew John. "Long baseline kinematic GPS." Thesis, University of Nottingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366412.
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Raheja, Sameer 1974. "Kinematic modeling with constraints." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/46111.
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13
Vytnova, Polina. "Kinematic fast dynamo problem." Thesis, University of Warwick, 2014. http://wrap.warwick.ac.uk/66400/.
Testo completoAbstract (sommario):
In the present work we develop an approach to the classical kinematic fast dynamo problem for flows [32] in the real 3-dimensional space. We suggest a fluid flow that may possibly generate a magnetic field which energy grows exponentially fast with time in the present of slow diffusivity. In order to verify the construction we study a discrete system and prove that an analogous statement holds true for the Poincaré map of the provisional flow and vector fields in the plane. This problem falls into the framework of open dynamical systems with random holes.
14
Tymianski, Vadim Jacob. "Air bearing kinematic coupling." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0014860.
Testo completo
15
Farrugia, Pierre. "Kinematic analysis of foldable structures." Thesis, University of Surrey, 2008. http://epubs.surrey.ac.uk/773678/.
Testo completoAbstract (sommario):
The main objective of the present research is to develop a general method for the kinematic analysis of foldable structures. This objective is achieved in terms of a method called 'matrix dependency constraint' (MDC method) which is described in this thesis. The MDC method involves algebraic formulation of the geometry, degrees of freedom at the joints and the support conditions of a foldable structure.
16
Barraja, Mathieu. "TOLERANCE ALLOCATION FOR KINEMATIC SYSTEMS." UKnowledge, 2004. http://uknowledge.uky.edu/gradschool_theses/315.
Testo completoAbstract (sommario):
A method for allocating tolerances to exactly constrained assemblies is developed. The procedure is established as an optimization subject to constraints. The objective is to minimize the manufacturing cost of the assembly while respecting an acceptable level of performance. This method is particularly interesting for exactly constrained components that should be mass-produced. This thesis presents the different concepts used to develop the method. It describes exact constraint theory, manufacturing variations, optimization concepts, and the related mathematical tools. Then it explains how to relate these different topics in order to perform a tolerance allocation. The developed method is applied on two relevant exactly constrained examples: multi-fiber connectors, and kinematic coupling. Every time a mathematical model of the system and its corresponding manufacturing variations is established. Then an optimization procedure uses this model to minimize the manufacturing cost of the system while respecting its functional requirements. The results of the tolerance allocation are verified with Monte Carlo simulation.
17
Schmiechen, Philipp. "Design of precision kinematic systems." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/12628.
Testo completo
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Whittier, William Brooks. "Kinematic Analysis of Tensegrity Structures." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/35909.
Testo completoAbstract (sommario):
Tensegrity structures consist of isolated compression members (rigid bars) suspended by a continuous network of tension members (cables). Tensegrity structures can be used as variable geometry truss (VGT) mechanisms by actuating links to change their length. This paper will present a new method of position finding for tensegrity structures that can be used for actuation as VGT mechanisms.
Tensegrity structures are difficult to understand and mathematically model. This difficulty is primarily because tensegrity structures only exist in specific stable tensegrity positions. Previous work has focused on analysis based on statics, dynamics, and virtual work approaches. This work considers tensegrity structures from a kinematic viewpoint. The kinematic approach leads to a better understanding of the conditions under which tensegrity structures exist in the stable positions. The primary understanding that comes from this kinematic analysis is that stable positions for tensegrity structures exist only on the boundaries of nonassembly of the structure. This understanding also allows the tensegrity positions to be easily found. This paper presents a method of position finding based on kinematic constraints and applies that method to several example tensegrity structures.<br>Master of Science
19
Hobbs, John D. "Kinematic morphology of space systems." Thesis, Open University, 2007. http://oro.open.ac.uk/54487/.
Testo completoAbstract (sommario):
This thesis considers the robustness to faults of mechanical kinematic systems typical of the type applied to the locomotion sub-systems of planetary exploration vehicles. It is argued that, whereas the electronic, software and control methodologies for such kinematic systems have received extensive attention, the development of the theory supporting the corresponding mechanical architectures has not received the same level of attention. An introduction to the space systems context of the topic is provided, and used to illustrate the nature of the requirements that evolve for such missions, concentrating on aspects of'terrainability' - the suitability of a vehicle to manoeuvre on rough planetary surfaces. An approach is investigated which takes concepts from graph theory and linear algebra, and uses these to establish a means for representing kinematic topologies, and, in particular, the 'fault graph' structures, and 'fault classes' that result from the progressive application of faults to nominal kinematic system configurations. Ways whereby the eigenvalues and eigenvectors of the characteristic polynomials of the interchange graph adjacency matrices of various kinematic systems can be applied to represent such systems under nominal and fault conditions are investigated, including development of the 'constraints matrix'. Additionally, the relevance of entropy within a fault graph context is considered, and also techniques suggested for analysing systems in a way which allows a richer representation of the underlying kinematic structure. Various metrics are considered and a means is established whereby a selection of parameters representing some aspects of kinematic systems' behaviour is used in conjunction with these to provide a means of comparing system configurations with each other, in terms of several 'intersystem distance' measures. Some success was achieved - 'inter-system distances' were derived for a selection of systems exhibiting different topologies and showed that these can usefully be used to represent some aspects of kinematic system topologies. Some evidence was obtained that it is possible to discriminate between tree-based and looped systems using this method.
20
Szatmari, Szabolcs. "Kinematic Calibration of Parallel Kinematic Machines on the Example of the Hexapod of Simple Design." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1194357963765-04082.
Testo completoAbstract (sommario):
The aim of using parallel kinematic motion systems as an alternative of conventional machine tools for precision machining has raised the demands made on the accuracy of identification of the geometric parameters that are necessary for the kinematic transformation of the motion variables. The accuracy of a parallel manipulator is not only dependent upon an accurate control of its actuators but also upon a good knowledge of its geometrical characteristics. As the platform's controller determines the length of the actuators according to the nominal model, the resulted pose of the platform is inaccurate. One way to enhance platform accuracy is by kinematic calibration, a process by which the actual kinematic parameters are identified and then implemented to modify the kinematic model used by the controller. The first and most general valuation criterion for the actual calibration approaches is the relative improvement of the motion accuracy, eclipsing the other aspects to pay for it. The calibration outlay has been underestimated or even neglected for a long time. The scientific value of the calibration procedure is not only in direct proportion to the achieved accuracy, but also to the calibration effort. These demands become particularly stringent in case of the calibration of hexapods of the so-called simple design. The objectives of the here proposed new calibration procedure are based on the deficits mentioned above under the special requirements due to the circumstances of the simple design-concept. The main goals of the procedure can be summarized in obtaining the basics for an automated kinematic calibration procedure which works efficiently, quickly, effectively and possibly low-cost, all-in-one economically applied to the parallel kinematic machines. The problem will be approached systematically and taking step by step the necessary conclu-sions and measurements through: Systematical analysis of the workspace to determine the optimal measuring procedure, measurements with automated data acquisition and evaluation, simulated measurements based on the kinematic model of the structure and identifying the kinematic parameters using efficient optimization algorithms. The presented calibration has been successfully implemented and tested on the hexapod of simple design `Felix' available at the IWM, TU Dresden. The obtained results encourage the application of the procedure to other hexapod structures.
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Szatmári, Szabolcs. "Kinematic Calibration of Parallel Kinematic Machines on the Example of the Hexapod of Simple Design." Dresden : Inst. für Werkzeugmaschinen und Steuerungstechnik, Lehrstuhl für Werkzeugmaschinen, 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016374557&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Testo completo
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Rojas, Nicolàs. "Distance-based formulations for the position analysis of kinematic chains." Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/83516.
Testo completoAbstract (sommario):
This thesis addresses the kinematic analysis of mechanisms, in particular, the position
analysis of kinematic chains, or linkages, that is, mechanisms with rigid bodies (links)
interconnected by kinematic pairs (joints). This problem, of completely geometrical
nature, consists in finding the feasible assembly modes that a kinematic chain can adopt.
An assembly mode is a possible relative transformation between the links of a kinematic
chain. When an assignment of positions and orientations is made for all links with
respect to a given reference frame, an assembly mode is called a configuration. The
methods reported in the literature for solving the position analysis of kinematic chains
can be classified as graphical, analytical, or numerical.
The graphical approaches are mostly geometrical and designed to solve particular
problems. The analytical and numerical methods deal, in general, with kinematic chains
of any topology and translate the original geometric problem into a system of kinematic analysis of all the Assur kinematic chains resulting from replacing some of its revolute
joints by slider joints. Thus, it is concluded that the polynomials of all fully-parallel
planar robots can be derived directly from that of the widely known 3-RPR robot. In
addition to these results, this thesis also presents an efficient procedure, based on distance
and oriented area constraints, and geometrical arguments, to trace coupler curves
of pin-jointed Gr¨ubler kinematic chains. All these techniques and results together are
contributions to theoretical kinematics of mechanisms, robot kinematics, and distance
plane geometry.
equations that defines the location of each link based, mainly, on independent loop
equations. In the analytical approaches, the system of kinematic equations is reduced
to a polynomial, known as the characteristic polynomial of the linkage, using different
elimination methods —e.g., Gr¨obner bases or resultant techniques. In the numerical
approaches, the system of kinematic equations is solved using, for instance, polynomial
continuation or interval-based procedures.
In any case, the use of independent loop equations to solve the position analysis
of kinematic chains, almost a standard in kinematics of mechanisms, has seldom been
questioned despite the resulting system of kinematic equations becomes quite involved
even for simple linkages. Moreover, stating the position analysis of kinematic chains
directly in terms of poses, with or without using independent loop equations, introduces
two major disadvantages: arbitrary reference frames has to be included, and all formulas
involve translations and rotations simultaneously. This thesis departs from this standard
approach by, instead of directly computing Cartesian locations, expressing the original
position problem as a system of distance-based constraints that are then solved using
analytical and numerical procedures adapted to their particularities.
In favor of developing the basics and theory of the proposed approach, this thesis
focuses on the study of the most fundamental planar kinematic chains, namely, Baranov
trusses, Assur kinematic chains, and pin-jointed Gr¨ubler kinematic chains. The results
obtained have shown that the novel developed techniques are promising tools for the
position analysis of kinematic chains and related problems. For example, using these
techniques, the characteristic polynomials of most of the cataloged Baranov trusses can
be obtained without relying on variable eliminations or trigonometric substitutions and
using no other tools than elementary algebra. An outcome in clear contrast with the
complex variable eliminations require when independent loop equations are used to tackle
the problem.
The impact of the above result is actually greater because it is shown that the
characteristic polynomial of a Baranov truss, derived using the proposed distance-based
techniques, contains all the necessary and sufficient information for solving the position<br>Esta tesis aborda el problema de análisis de posición de cadenas cinemáticas, mecanismos con cuerpos rígidos (enlaces)
interconectados por pares cinemáticos (articulaciones). Este problema, de naturaleza geométrica, consiste en encontrar los
modos de ensamblaje factibles que una cadena cinemática puede adoptar. Un modo de ensamblaje es una transformación
relativa posible entre los enlaces de una cadena cinemática. Los métodos reportados en la literatura para la solución del análisis
de posición de cadenas cinemáticas se pueden clasificar como gráficos, analíticos o numéricos.
Los enfoques gráficos son geométricos y se diseñan para resolver problemas particulares. Los métodos analíticos y numéricos
tratan con cadenas cinemáticas de cualquier topología y traducen el problema geométrico original en un sistema de ecuaciones
cinemáticas que define la ubicación de cada enlace, basado generalmente en ecuaciones de bucle independientes. En los
enfoques analíticos, el sistema de ecuaciones cinemáticas se reduce a un polinomio, conocido como el polinomio característico
de la cadena cinemática, utilizando diferentes métodos de eliminación. En los métodos numéricos, el sistema se resuelve
utilizando, por ejemplo, la continuación polinomial o procedimientos basados en intervalos.
En cualquier caso, el uso de ecuaciones de bucle independientes, un estándar en cinemática de mecanismos, rara vez ha sido
cuestionado a pesar de que el sistema resultante de ecuaciones es bastante complicado, incluso para cadenas simples. Por otra
parte, establecer el análisis de la posición de cadenas cinemáticas directamente en términos de poses, con o sin el uso de
ecuaciones de bucle independientes, presenta dos inconvenientes: sistemas de referencia arbitrarios deben ser introducidos, y
todas las fórmulas implican traslaciones y rotaciones de forma simultánea. Esta tesis se aparta de este enfoque estándar
expresando el problema de posición original como un sistema de restricciones basadas en distancias, en lugar de directamente
calcular posiciones cartesianas. Estas restricciones son posteriormente resueltas con procedimientos analíticos y numéricos
adaptados a sus particularidades.
Con el propósito de desarrollar los conceptos básicos y la teoría del enfoque propuesto, esta tesis se centra en el estudio de las
cadenas cinemáticas planas más fundamentales, a saber, estructuras de Baranov, cadenas cinemáticas de Assur, y cadenas
cinemáticas de Grübler. Los resultados obtenidos han demostrado que las técnicas desarrolladas son herramientas
prometedoras para el análisis de posición de cadenas cinemáticas y problemas relacionados. Por ejemplo, usando dichas
técnicas, los polinomios característicos de la mayoría de las estructuras de Baranov catalogadas se puede obtener sin realizar
eliminaciones de variables o sustituciones trigonométricas, y utilizando solo álgebra elemental. Un resultado en claro contraste
con las complejas eliminaciones de variables que se requieren cuando se utilizan ecuaciones de bucle independientes.
El impacto del resultado anterior es mayor porque se demuestra que el polinomio característico de una estructura de Baranov,
derivado con las técnicas propuestas, contiene toda la información necesaria y suficiente para resolver el análisis de posición de
las cadenas cinemáticas de Assur que resultan de la sustitución de algunas de sus articulaciones de revolución por
articulaciones prismáticas. De esta forma, se concluye que los polinomios de todos los robots planares totalmente paralelos se
pueden derivar directamente del polinomio característico del conocido robot 3-RPR. Adicionalmente, se presenta un
procedimiento eficaz, basado en restricciones de distancias y áreas orientadas, y argumentos geométricos, para trazar curvas
de acoplador de cadenas cinemáticas de Grübler. En conjunto, todas estas técnicas y resultados constituyen contribuciones a la
cinemática teórica de mecanismos, la cinemática de robots, y la geometría plana de distancias.
Barcelona 13-
23
Fabricius, Maximilian Hieronymus [Verfasser], and Ralf [Akademischer Betreuer] Bender. "Kinematics across bulge types : a longslit kinematic survey and dedicated instrumentation / Maximilian Hieronymus Fabricius. Betreuer: Ralf Bender." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2012. http://d-nb.info/1023930382/34.
Testo completo
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Löfgren, Björn. "Kinematic control of redundant knuckle booms." Licentiate thesis, KTH, Machine Design, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1731.
Testo completoAbstract (sommario):
<p>A kinematically redundant four degrees of freedommanipulator arm, a knuckle boom, is studied. Three joints arerevolute and one linear. Since only three degrees of freedomare needed for positioning, we have one redundant degree offreedom. Three different kinematic control strategies arestudied. One is based on the maximization of velocity (localoptimisation). This strategy is non-repeatable and cansometimes lead to kinematically unfavourable positions. In thesecond strategy, which is based on the maximization of staticlifting capacity (local optimisation), one of the degrees offreedom (the linear joint) is made a function of the toolcentre point position. The third strategy, which is based ondynamic programming (global optimization), calculates theshortest time that is possible for the tool centre point to gofrom one point to another point in the working area. The threestrategies are compared in a simulation study. The simulationsshow the necessary speed requirements for all joints whenperforming straight paths in the manipulator work area. Thesimulations also show the difference in time consumptionsbetween the three control algorithms and also what happens whenthe joints reach their maximum velocity limits.</p><p><strong>Keywords</strong>Manipulator, Kinematic Control, RedundantLanguage</p>
25
Mashali, Mustafa. "Kinematic Control of Redundant Mobile Manipulators." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5989.
Testo completoAbstract (sommario):
A mobile manipulator is a robotic arm mounted on a robotic mobile platform. In such a system, the degrees of freedom of the mobile platform are combined with that of the manipulator. As a result, the workspace of the manipulator is substantially extended. A mobile manipulator has two trajectories: the end-effector trajectory and the mobile platform trajectory. Typically, the mobile platform trajectory is not defined and is determined through inverse kinematics. But in some applications it is important to follow a specified mobile platform trajectory. The main focus of this work is to determine the inverse kinematics of a mobile manipulator to follow the specified end-effector and mobile platform trajectories, especially when both trajectories cannot be exactly followed simultaneously due to physical limitations. Two new control algorithms are developed to solve this problem.
In the first control algorithm, three joint-dependent control variables (spherical coordinates D, α and β) are introduced to define the mobile platform trajectory in relation to the end-effector trajectory and vice versa. This allows direct control of the mobile platform motion relative to the end-effector. Singularity-robust and task-priority inverse kinematics with gradient projection method is used to find best possible least-square solutions for the dual-trajectory tracking while maximizing the whole system manipulability. MATLAB Simulated Planar Mobile Manipulation is used to test and optimize the proposed control system. The results demonstrate the effectiveness of the control system in following the two trajectories as much as possible while optimizing the whole system manipulability measure.
The second new inverse kinematics algorithm is introduced when the mobile platform motion is restricted to stay on a specified virtual or physical track. The control scheme allows xii the mobile manipulator to follow the desired end-effector trajectory while keeping the mobile platform on a specified track. The mobile platform is moved along a track to position the arm at a pose that facilitates the end-effector task. The translation of the redundant mobile manipulator over the mobile platform track is determined by combining the mobility of the platform and the manipulation of the redundant arm in a single control system. The mobile platform is allowed to move forward and backward with different velocities along its track to enable the end-effector in following its trajectory. MATLAB simulated 5 DoF redundant planar mobile manipulator is used to implement and test the proposed control algorithm. The results demonstrate the effectiveness of the control system in adjusting the mobile platform translations along its track to allow the arm to follow its own trajectory with high manipulability. Both control algorithms are implemented on MATLAB simulated wheelchair mounted robotic arm system (WMRA-II). These control algorithms are also implemented on real the WMRA-II hardware.
In order to facilitate mobile manipulation, a control motion scheme is proposed to detect and correct the mobile platform pose estimation error using computer vision algorithm. The Iterative Closest Point (ICP) algorithm is used to register two consecutive Microsoft Kinect camera views. Two local transformation matrices i. e., Encoder and ICP transformation matrices, are fused using Extended Kalman Filter (EKF) to filter the encoder pose estimation error. VICON motion analysis system is used to capture the ground truth of the mobile platform. Real time implementation results show significant improvement in platform pose estimation. A real time application involving obstacle avoidance is used to test the proposed updated motion control system.
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Chan, Tsz-pan Henry, and 陳子斌. "Morpho-kinematic modeling of planetary nebulae." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42182293.
Testo completo
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Hobbs, Catherine Ann. "On kinematic singularities of low dimension." Thesis, University of Liverpool, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359195.
Testo completoAbstract (sommario):
This thesis is an investigation into the types of singularities that can appear on trajectories of rigid motions, kinematic singularities, motivated by problems in mechanical engineering of designing mechanisms. Here we consider rigid motions of the plane and space with one and two degrees of freedom. In order to study these singularities weprove a multi-germ transversality result and also a result about the restrictions on the codimension of the singularity given by the number of degrees of freedom of the motion. Some of the classifications of the singularities we are interested in have already been completed but all the simple singularities of space curves and also most of the multi-germs, both of the plane and of space, are classified here. We also study the unfoldings and bifurcation sets of all the kinematic singularities on our lists.
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Grinker, Barry. "Accuracy of shipborne kinematic GPS surveying." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/26341.
Testo completo
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Bausch, John Jacob. "Kinematic methods for automated fixture design." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/13978.
Testo completo
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Osborn, Matthew C. 1970. "Kinematic scaling in quasielastic electron scattering." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/35043.
Testo completo
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Barragán, Patrick R. "Interactive Bayesian identification of kinematic mechanisms." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/100117.
Testo completoAbstract (sommario):
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 127-128).<br>This thesis addresses the problem of identifying mechanisms based on data gathered from a robot's interaction with them. We present a decision-theoretic formulation of this problem, using Bayesian filtering techniques to maintain a distributional estimate of the mechanism type and parameters. We begin by implementing a discrete Bayesian filter. We demonstrate the approach on a domain with four primitive and two composite mechanisms. In order to reduce the amount of interaction required to arrive at a confident identification, we select actions explicitly to either a) reduce entropy in the current estimate or b) race the top two hypotheses to clearly distinguish between them. The results show that this approach can correctly identify complex mechanisms including mechanisms which behave different in different parts of their configuration spaces. The results also show that active action selection can significantly decrease the number of actions required to gather the same information while the racing technique does so without increasing step time of the filter over random action selection. We analyze Bayesian filtering in a hybrid space for model comparison. We discuss the appropriateness of continuous state-space, parametric filters for the mechanism identification problem. We seek an alternative strategy because no parametric form is clearly suited to representing the posterior distributions during the filtering process. We find that Bayesian filtering in the hybrid space has some surprising consequences and discuss their effect on inference. Finally, we implement a particle filter which allows filtering in a space expanded from 10 model-parameter pairs to 50,000. We demonstrate that with high accuracy, the particle filter can correctly identify the mechanism type. More crucially, we show that the filter's estimate allows the robot to reasonably predict the motion of the given mechanism regardless of classification. We demonstrate our method in simulation and on a real-world PR2 robot interacting with common mechanisms.<br>by Patrick Rene Barragán.<br>Ph. D.
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NARUK, STEPHEN JOHN. "KINEMATIC SIGNIFICANCE OF MYLONITIC FOLIATION (METAMORPHIC)." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184087.
Testo completoAbstract (sommario):
Geometric analyses of three mylonite zones, including two metamorphic-core-complex SC-mylonite zones, show that the mylonitic foliation surfaces (S-surfaces) are consistently discordant to the margins of the shear zones. Finite-strain analyses show that the foliation surfaces in each zone are consistently oriented parallel to the XY-plane of the finite strain ellipsoid. The shear bands within the mylonites (C-surfaces, C'-surfaces, extensional crenulations, and shear-band cleavages) are uniformly oriented subparallel to the margins of the shear zones. The finite lengths and discontinuous natures of the shear bands require that the displacement along them be accommodated by the S-surfaces at the tips of the shear bands. Thus the S-surface elongations and orientations represent the total bulk rock strain, rather than some minimum measure of inter-C-surface strain. General stress and strain considerations indicate that the shear bands are planes of maximum shear stress, and that they are not only simple-shear slip planes. This interpretation implies that in simple-shear deformation, a single, irrotational set of shear bands will develop parallel to the shear-zone boundaries. In deformations involving significant components of coaxial strain, however, shear bands may develop in other orientations or in conjugate sets and rotate with progressive deformation.
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Waterson, Hugh Benedict. "Kinematic alignment and total knee arthroplasty." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31190.
Testo completoAbstract (sommario):
Osteoarthritis (OA) is one of the leading causes of global disability. Surgical intervention in the form of Total Knee Arthroplasty (TKA) has been established as an excellent treatment modality for people with OA who experience joint symptoms that have a substantial impact on their quality of life and are refractory to non-surgical treatment. In the 1970s the concept of implanting TKAs in mechanical alignment (MA) was developed as a compromise to confer mechanical advantage to the prosthesis, ignoring the patient's natural anatomy, to prevent early failure of the implant. Until now, this compromise has not been revisited. Satisfaction following TKA remains inferior to total hip arthroplasty. The cause of this dissatisfaction is not clear. Implant survival is no longer comparable to that of the early designs of TKA, and recent studies have suggested that deviation from neutral alignment does not have the detrimental effect on survivorship as previously thought. In an attempt to improve patient satisfaction following TKA a new technique has been developed whereby the prostheses are implanted in such a way as to recreate the alignment of the knee in the patient's pre-arthritic state. This has been termed natural or kinematic alignment (KA). This thesis examines the impact of KA in TKA with the primary hypothesis that TKA performed utilising KA would lead to improved functional outcome following surgery compared to that of MA. An initial single surgeon proof of concept case series of 25 patients was performed to look at the precision of new patient specific cutting blocks. The results suggested that the cutting blocks were accurate in producing the desired cuts. Following the proof of concept case series, a feasibility study was then performed comparing the new KA technique with the standard MA technique. The feasibility study familiarised the operating surgeons with the new technology in preparation for a Randomised Control Trial (RCT). A prospective blinded RCT was performed to compare the functional outcome of patients implanted with TKA in MA with that of KA. A total of 71 patients undergoing TKA were randomised to either MA (n=35) or KA (n=36). Preand post-operative hip knee ankle (HKA) radiographs were analysed. A number of patient reported outcome measures and functional tests were assessed pre-operatively, 6 weeks, 3 months, 6 months, and at 1 year post-operation. The cutting guides were accurate. There were no statistically significant differences between the MA and KA groups at 1 year. A cohort of post-menopausal women with unilateral osteoarthritis treated with TKA utilising the KA philosophy had dual energy x-ray absorptiometry scans 1.5 years post-operatively using a modified validated densitometric analysis protocol, to assess peri-prosthetic Bone Mineral Density (BMD). The contralateral knee was scanned so that relative bone mineral density could be calculated. Statistical analysis revealed no significant difference in relative peri-prosthetic bone mineral density due to variation in implant position with respect to the Lateral Distal Femoral Angle (LDFA) and the Medial Proximal Tibial Angle (MPTA). There was a significant correlation with overall HKA angle and the relative BMD under the medial side of the tibial tray. KA TKAs appear to have comparable short-term results to MA TKAs with no significant differences in function 1 year post-operatively. Overall HKA angle rather than the individual component position caused change in relative BMD under the tibial tray, therefore aiming for an anatomical joint line may improve kinematics without a detrimental effect on the implant. Further research is required to see if any theoretical long-term functional benefits of KA are realised or if there are any potential effects on implant survival.
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Jennen, Hendrik [UNESP]. "Dark energy as a kinematic effect." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/134324.
Testo completoAbstract (sommario):
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Previous issue date: 2016-02-12<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Observações realizadas nas últimas três décadas confirmaram que o universo se encontra em um estado de expansão acelerada. Essa aceleração é atribuída à presença da chamada energia escura, cuja origem permanece desconhecida. A maneira mais simples de se modelar a energia escura consiste em introduzir uma constante cosmológica positiva nas equações de Einstein, cuja solução no vácuo é então dada pelo espaço de de Sitter. Isso, por sua vez, indica que a cinemática subjacente ao espaço-tempo deve ser aproximadamente governada pelo grupo de de Sitter SO(1,4), e não pelo grupo de Poincaré ISO(1,3). Nesta tese, adotamos tal argumento como base para a conjectura de que o grupo que governa a cinemática local é o grupo de de Sitter, com o desvio em relação ao grupo de Poincaré dependendo ponto-a-ponto do valor de um termo cosmológico variável. Com o propósito de desenvolver tal formalismo, estudamos a geometria de Cartan na qual o espaço modelo de Klein é, em cada ponto, um espaço de de Sitter com o conjunto de pseudo-raios definindo uma função não-constante do espaço-tempo. Encontramos que o tensor de torção nessa geometria adquire uma contribuição que não está presente no caso de uma constante cosmológica. Fazendo uso da teoria das realizações não-lineares, estendemos a classe de simetrias do grupo de Lorentz SO(1,3) para o grupo de de Sitter. Em seguida, verificamos que a estrutura da gravitação teleparalela--- uma teoria gravitacional equivalente à relatividade geral--- é uma geometria de Riemann-Cartan não linear. Inspirados nesse resultado, construímos uma generalização da gravitação teleparalela sobre uma geometria de de Sitter--Cartan com um termo cosmológico dado por uma função do espaço-tempo, a qual é consistente com uma cinemática localmente governada pelo grupo de de Sitter. A função cosmológica possui sua própria dinâmica e emerge naturalmente acoplada não-minimalmente ao campo gravitacional, analogamente ao que ocorre nos modelos telaparalelos de energia escura ou em teorias de gravitação escalares-tensoriais. Característica peculiar do modelo aqui desenvolvido, a função cosmológica fornece uma contribuição para o desvio geodésico de partículas adjacentes em queda livre. Embora tendo sua própria dinâmica, a energia escura manifesta-se como um efeito da cinemática local do espaço-tempo.<br>Observations during the last three decades have confirmed thatthe universe momentarily expands at an accelerated rate, which is assumed to be driven by dark energy whose origin remains unknown. The minimal manner of modelling dark energy is to include a positive cosmological constant in Einstein's equations, whose solution in vacuum is de Sitter space. This indicates that the large-scale kinematics of spacetime is approximated by the de Sitter group SO(1,4) rather than the Poincaré group ISO(1,3). In this thesis we take this consideration to heart and conjecture that the group governing the local kinematics of physics is the de Sitter group, so that the amount to which it is a deformation of the Poincaré group depends pointwise on the value of a nonconstant cosmological function. With the objective of constructing such a framework we study the Cartan geometry in which the model Klein space is at each point a de Sitter space for which the combined set of pseudoradii forms a nonconstant function on spacetime. We find that the torsion receives a contribution that is not present for a cosmological constant. Invoking the theory of nonlinear realizations we extend the class of symmetries from the Lorentz group SO(1,3) to the enclosing de Sitter group. Subsequently, we find that the geometric structure of teleparallel gravity--- a description for the gravitational interaction physically equivalent to general relativity--- is a nonlinear Riemann--Cartan geometry.This finally inspires us to build on top of a de Sitter--Cartan geometry with a cosmological function a generalization of teleparallel gravity that is consistent with a kinematics locally regulated by the de Sitter group. The cosmological function is given its own dynamics and naturally emerges nonminimally coupled to the gravitational field in a manner akin to teleparallel dark energy models or scalar-tensor theories in general relativity. New in the theory here presented, the cosmological function gives rise to a kinematic contribution in the deviation equation for the world lines of adjacent free-falling particles. While having its own dynamics, dark energy manifests itself in the local kinematics of spacetime.
35
Jennen, Hendrik Gerard Johan. "Dark energy as a kinematic effect/." São Paulo, 2016. http://hdl.handle.net/11449/134324.
Testo completoAbstract (sommario):
Orientador: José Geraldo Pereira<br>Banca: Ruben Aldrovandi<br>Banca: Rogério Rosenfeld<br>Banca: Oliver Fabio Piatella<br>Banca: José Wadih Maluf<br>Resumo: Observações realizadas nas últimas três décadas confirmaram que o universo se encontra em um estado de expansão acelerada. Essa aceleração é atribuída à presença da chamada energia escura, cuja origem permanece desconhecida. A maneira mais simples de se modelar a energia escura consiste em introduzir uma constante cosmológica positiva nas equações de Einstein, cuja solução no vácuo é então dada pelo espaço de de Sitter. Isso, por sua vez, indica que a cinemática subjacente ao espaço-tempo deve ser aproximadamente governada pelo grupo de de Sitter SO(1,4), e não pelo grupo de Poincaré ISO(1,3). Nesta tese, adotamos tal argumento como base para a conjectura de que o grupo que governa a cinemática local é o grupo de de Sitter, com o desvio em relação ao grupo de Poincaré dependendo ponto-a-ponto do valor de um termo cosmológico variável. Com o propósito de desenvolver tal formalismo, estudamos a geometria de Cartan na qual o espaço modelo de Klein é, em cada ponto, um espaço de de Sitter com o conjunto de pseudo-raios definindo uma função não-constante do espaço-tempo. Encontramos que o tensor de torção nessa geometria adquire uma contribuição que não está presente no caso de uma constante cosmológica. Fazendo uso da teoria das realizações não-lineares, estendemos a classe de simetrias do grupo de Lorentz SO(1,3) para o grupo de de Sitter. Em seguida, verificamos que a estrutura da gravitação teleparalela--- uma teoria gravitacional equivalente à relatividade geral--- é uma geometria de Riemann-Cartan não linear. Inspirados nesse resultado, construímos uma generalização da gravitação teleparalela sobre uma geometria de de Sitter--Cartan com um termo cosmológico dado por uma função do espaço-tempo, a qual é consistente com uma cinemática localmente governada pelo grupo de de Sitter. A função cosmológica possui sua própria dinâmica e emerge na...<br>Abstract: Observations during the last three decades have confirmed that the universe momentarily expands at an accelerated rate, which is assumed to be driven by dark energy whose origin remains unknown. The minimal manner of modelling dark energy is to include a positive cosmological constant in Einstein's equations, whose solution in vacuum is de Sitter space. This indicates that the large-scale kinematics of spacetime is approximated by the de Sitter group SO(1,4) rather than the Poincaré group ISO(1,3). In this thesis we take this consideration to heart and conjecture that the group governing the local kinematics of physics is the de Sitter group, so that the amount to which it is a deformation of the Poincaré group depends pointwise on the value of a nonconstant cosmological function. With the objective of constructing such a framework we study the Cartan geometry in which the model Klein space is at each point a de Sitter space for which the combined set of pseudoradii forms a nonconstant function on spacetime. We find that the torsion receives a contribution that is not present for a cosmological constant. Invoking the theory of nonlinear realizations we extend the class of symmetries from the Lorentz group SO(1,3) to the enclosing de Sitter group. Subsequently, we find that the geometric structure of teleparallel gravity--- a description for the gravitational interaction physically equivalent to general relativity--- is a nonlinear Riemann--Cartan geometry.This finally inspires us to build on top of a de Sitter--Cartan geometry with a cosmological function a generalization of teleparallel gravity that is consistent with a kinematics locally regulated by the de Sitter group. The cosmological function is given its own dynamics and naturally emerges nonminimally coupled to the gravitational field in a manner akin to teleparallel dark energy models or scalar-tensor theories in general relativity. New in...<br>Doutor
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Reidy, John Joseph. "A kinematic analysis of redundant manipulators /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487267546982074.
Testo completo
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Sander, Elizabeth J. "Kinematic demands of nucleus arthroplasty technology." View the abstract Download the full-text PDF version, 2008. http://etd.utmem.edu/ABSTRACTS/2008-044-Sander-index.htm.
Testo completoAbstract (sommario):
Thesis (M.S.)--University of Tennessee Health Science Center, 2008.<br>Title from title page screen (viewed on February 24, 2009). Research advisor: Denis DiAngelo Ph.D. Document formatted into pages (viii, 59 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 42-46).
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Chan, Tsz-pan Henry. "Morpho-kinematic modeling of planetary nebulae." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42182293.
Testo completo
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Vieth, Kai-Uwe. "Kinematic wavefield attributes in seismic imaging /." [Karlsruhe] : Die Universität, 2001. http://www.ubka.uni-karlsruhe.de/vvv/2001/physik/2/2.pdf.
Testo completo
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Merdith, Andrew. "Kinematic Plate Models of the Neoproterozoic." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/17715.
Testo completoAbstract (sommario):
Plate tectonic reconstructions traditionally use a combination of palaeomagnetic and geological data to model the changing positions of continents throughout Earth history. Plate reconstructions are particularly useful because they provide a framework for testing a range of hypotheses pertaining to climate, seawater chemistry, evolutionary patterns and the relationship between mantle and surface. During the Mesozoic and Cenozoic these are underpinned by data from the ocean basins that preserve relative plate motions, and data from hotspot chains and tomographic imaging of subducted slabs within the mantle to constrain absolute plate motions. For earlier times, neither ocean basins nor subducted slabs are preserved to assist with constructing plate models. Previously published plate models are usually built around times that have high quality palaeomagnetic data and between these times, the motion of continental crust is usually interpolated. Alternatively, regional tectonic models are developed predominantly from using geological data but without integrating the model into a global context. Additionally, until now all global plate models for the Neoproterozoic model only describe the configurations of continental blocks and do not explicitly consider the spatial and temporal evolution of plate boundaries. In this thesis, I present the first topological plate model of the Neoproterozoic that traces the dynamic evolution and interaction of tectonic plates, which encompass the entire earth. This model synthesises new geological and palaeomagnetic data, along with conclusions drawn from kinematic data to help discriminate competing continental configurations of the western area of the Neoproterozoic supercontinent, Rodinia. The thesis concludes by analysing the supercontinent cycle from 1000 to 0 Ma, by extracting the rift length, subduction zone length and perimeter-to-area ratio of continental crust to better understand the long-term evolution of our planet.
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Hunter, Elise Hansen. "Speech Adaptation to Kinematic Recording Sensors." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/5728.
Testo completoAbstract (sommario):
This thesis examined the time course of speech adaptation prior to data collection when using an electromagnetic articulograph to measure speech articulator movements. The stimulus sentence and electromagnetic sensor placement were designed to be sensitive to changes in the fricatives /s/ and /ʃ/. Twenty native English speakers read aloud stimulus sentences before the attachment of six electromagnetic sensors, immediately after attachment, and again at 5, 10, 15 and 20 minutes after attachment. Participants read aloud continuously between recordings to encourage adaptation to the presence of the sensors. Audio recordings were rated by 20 native English listeners who were not part of the production study. After listening to five practice samples, these participants rated 150 stimuli (31 repeat samples) using a visual analog scale (VAS) with the endpoints labeled as precise and imprecise. An acoustic analysis of the recordings was done by segmenting the fricatives /s/ and /ʃ/ from the longer recording and computing spectral center of gravity and spectral standard deviation in Hertz. Durations of /s/, /ʃ/ and the sentence were also measured. Results of both perceptual and acoustic analysis revealed a change in speech precision over time, with all post attachment recordings receiving lower perceptual scores. Precision ratings beyond the ten minute recording remained steady. It can be concluded from the results that participants reached a height of adaptation after 10 minutes of talking with kinematic recording sensors attached, and that after the attachment of sensors, speech production precision did not at any point return to pre attachment levels.
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Bruni, Danilo <1978>. "Intraoperative kinematic evaluation with navigation system and postoperative kinematic evaluation with dynamic RSA of total knee arthroplasty." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6450/1/bruni_danilo_tesi.pdf.
Testo completoAbstract (sommario):
Restoring a correct implant kinematics and providing a good ligament balance and patellar tracking is mandatory to improve clinical and functional outcome after a Total Knee Replacement. Surgical navigation systems are a reliable and accurate tool to help the surgeon in achieving these goals. The aim of the present study was to use navigation system with an intra-operative surgical protocol to evaluate and determine an optimal implant kinematics during a Total Knee Replacement.
43
Bruni, Danilo <1978>. "Intraoperative kinematic evaluation with navigation system and postoperative kinematic evaluation with dynamic RSA of total knee arthroplasty." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6450/.
Testo completoAbstract (sommario):
Restoring a correct implant kinematics and providing a good ligament balance and patellar tracking is mandatory to improve clinical and functional outcome after a Total Knee Replacement. Surgical navigation systems are a reliable and accurate tool to help the surgeon in achieving these goals. The aim of the present study was to use navigation system with an intra-operative surgical protocol to evaluate and determine an optimal implant kinematics during a Total Knee Replacement.
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Veselka, Michal. "Měření a analýza kinematiky zadního víceprvkového zavěšení." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230580.
Testo completoAbstract (sommario):
This diploma thesis deals with the measurement of kinematic points of rear multilink suspension using 3D optical scanners TRITOP and ATOS and developing a measurement methodology of similar types of suspension with these scanners. Subsequently, kinematic features of this suspension are analyzed using the multibody system MSC.ADAMS / Car.
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Налимова, П. Н., та А. В. Скорик. "Вариант представления основных понятий кинематики в блоковой форме". Thesis, Сумский государственный университет, 2015. http://essuir.sumdu.edu.ua/handle/123456789/39908.
Testo completo
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Borgia, Fabio. "Kinematic optimization of an overboarding chute mechanism." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
Cerca il testo completoAbstract (sommario):
I had the opportunity to develop my thesis during the Internship Program at F.lli Righini, a world leader in designing and manufacturing offshore equipment.
I was tasked with improving the mechanical efficiency of an umbilical lay system. Instead of laying the cable on the sea floor, the Client wished to have it partially floating.
A new system had to be devised whereby a number of buoyancy modules had to be installed on the cable itself, an operation complicated by the fact that it could not be performed by a traditional fixed chute.
To solve this challenge, Righini suggested an innovative kinematic chute able to perform a certain rotation, thereby fully satisfying the requisites.
The aim of this master thesis is to optimize this prototype system. A MATLAB code will be created to conduct a meticulous structural analysis of the kinematic chute, to see if the piston which activates the whole chute rotation can be optimized in terms of weight and cost.
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Menghini, Massimiliano. "UIO based quadrotor FDI using kinematic model." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18064/.
Testo completoAbstract (sommario):
This thesis addresses the fault diagnosis problem
of sensors of a quadcopter system based on GNSS/IMU. The
model considered is a rigid body with 6DoF. Considering its
linearized kinematic model, the proposed FDI scheme is based
on a generalized bank of observers (GBO) designed with the
UIO theory. The fault scenario is composed by multiple but not concurrent faults. The designed scheme is tested using detectability and isolability analysis, identifying the weaknesses of the FDI scheme and investigating appropriate solutions for the fault diagnosis purposes. Afterwards, the scheme was reconfigured by applying the proposed solutions and analyzing that all the requirements in terms of isolability and detectability were met.
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Cocard, Marc Marcel. "High precision GPS processing in kinematic mode /." Zürich, 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10874.
Testo completo
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Ustun, Deniz. "Kinematic And Force Analyses Of Overconstrained Mechanisms." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613880/index.pdf.
Testo completoAbstract (sommario):
This thesis comprises a study on the kinematic and force analyses of the
overconstrained mechanisms. The scope of the overconstrained mechanisms is too
wide and difficult to handle. Therefore, the study is restricted to the planar
overconstrained mechanisms. Although the study involves only the planar
overconstrained mechanisms, the investigated methods and approaches could be
extended to the spatial overconstrained mechanisms as well.
In this thesis, kinematic analysis is performed in order to investigate how an
overconstrained mechanism can be constructed. Four methods are used. These are
the analytical method, the method of cognates, the method of combining identical
modules and the method of extending an overconstrained mechanism with extra links.
This thesis also involves the force analysis of the overconstrained mechanisms. A
method is introduced in order to eliminate the force indeterminacy encountered in the
overconstrained mechanisms. The results are design based and directly associated
with the assembly phase of the mechanism.
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Urakubo, Takateru. "Control of Dynamical Systems with Kinematic Constraints." 京都大学 (Kyoto University), 2001. http://hdl.handle.net/2433/150262.
Testo completo