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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Hodnocení změn kvality chůze tanečníků v porovnání s běžnou populací. / The evaluating of the change of walking quality in dancers in comparison with the normal population

Korošová, Kateřina January 2014 (has links)
Thesis name: The evaluating of the change of walking quality in dancers in comparison with the normal population Thesis goal: This thesis deals with effect of long-term ballet dance on kinematic parameters of gait. The theoretical part includes basic characteristics of gait cycle and kinesiological and biomechanical findings of ballet movement and its compensatory mechanisms in musculoskeletal system. There is analyzed angular parameters of gait cycle in ballet dancers in performance of walking in the experimental part. The results will show if the many-years intensive training of dance affects the alignment of particular joints of the body during human walk. Method: Kinematic analysis by Qualisys system allowing automatic processing of record obtained with infrared cameras. Qualisys uses its own high-frequency cameras for precise movement tracking of the measured object using active or passive markers. Gathered data from device were processed and statictically evaluated with Microsoft Office Excel. Keywords: gait, bipedal locomotion, dance, gait analysis, gait of dancers, ballet, kinematics analysis
22

Fylogenetické souvislosti lidské lokomoce realizované prostřednictvím ramenního pletence / Phylogenetical consequenses of human locomotion realizated during the schoulder girdle

Ryšánková, Lenka January 2014 (has links)
Title: Phylogenetical consequenses of human locomotion realizated during the schoulder girdle Objectives: Description of phylogenetic context of human locomotion realized through the shoulder girdle Methods: Study and analysis of the available literature Analytic-synthetic comparison of the current knowledge of evolution Study of available sources of phylogeny of locomotion in terrestrial vertebrates Results: It was found similarity in the basic control of human bipedal locomotion to control of quadrupedal locomotion of other animals and similarity in the specific form of human locomotion to locomotion of non-human primates Keywords: Bipedal locomotion, quadrupedal locomotion, control of locomotion, interlimb coordination
23

Passive control of mechanical systems

Adolfsson, Jesper January 2001 (has links)
No description available.
24

Application of Product Design Concepts and Hybrid System Dynamics to Demonstrate Zeno Behavior and Zeno Periodic Orbits in a Physical Double Pendulum Setup

Kothapalli, Bhargav 2011 May 1900 (has links)
This thesis aims to explain how the concepts of functional modeling are implemented in the development and validation of real-world hybrid dynamic systems. I also discuss how control theory is integrated with the design process in order to understand the significance of periodic orbits on a simple dynamic system. Two hybrid system applications with different levels of complexity will be considered in this thesis – an anthropomorphic Bipedal walking robot and a Double Pendulum with a mechanical stop. The primary objectives of this project are to demonstrate the phenomena of Zeno and zeno periodic orbits in hybrid dynamic systems involving impacts. Initially, I describe the salient features of the product design procedure and then explain the significance of functional modeling as a part of this process. We then discuss hybrid dynamic systems and the occurrence of Zeno behavior in their mathematical form. Also, the necessary conditions for existence of Zeno and zeno equilibrium points are provided. Then the theory of completed Lagrangian hybrid systems is explained in detail. We then examine the two hybrid dynamic systems being considered for this project. Prior research undertaken on bipedal walking is explored to understand their design and achievement of stable walking gaits with appropriate actuation mechanisms. Based on this insight, a suitable design procedure is employed to develop the bipedal robot model. The desired actuation mechanisms for all the configurations considered for this model as well as the challenges faced in employing optimal actuation will be discussed. However, due to the high level of complexity of the bipedal robot model, a simpler hybrid dynamic system is considered to simplify fabrication and control of the model. This is the motivation behind designing and building the Double Pendulum model with a mechanical stop in an attempt to observe zeno behavior in this system. We begin by formally demonstrating that the “constrained” double pendulum model displays Zeno behavior and complete this Zeno hybrid system to allow for solutions to be carried past the Zeno point. The end result is periods of unconstrained and constrained motions in the pendulum, with transitions to the constrained motion occurring at the Zeno point. We then consider the development of a real physical pendulum with a mechanical stop and introduce non-plastic impacts. Later, we verify through experimentation that Zeno behavior provides an accurate description of the behavior of the physical system. This provides evidence to substantiate the claim that Zeno behavior, while it does not technically occur in reality, provides an accurate method for predicting the behavior of systems undergoing impacts and that the theory developed to understand Zeno behavior can be applied to better understand these systems.
25

Passive control of mechanical systems

Adolfsson, Jesper January 2001 (has links)
No description available.
26

Experimental study of a novel actively assisted bipedal walker – simulation, modeling and experiment

Balakrishnan, Nishant 09 April 2015 (has links)
This thesis covers the study of an actively assisted passive walker with discontinuous and impulsive actuation. The dynamics of the passive and active portions are derived, and a comprehensive mathematical model is proposed. An actuation method is also proposed to study the use of multiple discrete actuation events in a walking gait. Two key cases are considered: actuation at the stance point and at the EA point of a non-kneed walker. An experimental walker was designed that is capable of passive walking and has an experimental implementation of the proposed actuation system. A thorough characterization of the model is then performed, with experimental validation to show that: at high ramp angles, energy injection results in an increase in BOA of ~38% on a stable walking gait at a Ct of 0.086, and at low ramp angles, injection results in a stride length increase of ~29% at a Ct of 0.06.
27

Utilizing a Computational Model for the Design of a Passive Dynamic Walker

Honeycutt, Craig Alan 01 January 2011 (has links)
Recent interest in using passive dynamic walkers (PDWs) for gait rehabilitation studies has presented a need for a robust, easily built mechanism. Unfortunately, these passive robots are hypersensitive to many variables outside of the usual design considerations that are studied when constructing them. By accentuating previous failures instead of suppressing them, this thesis presents a number of problematic situations commonly experienced when testing and tuning a PDW. Further, through a complete design of a 4-legged PDW with knees, simple design axioms brought about by myself and others are put into a practical context and applied directly to design. This thesis aspires to present a systematic design process, and highlight how a computational model can be used with both hand calculations and CAD packages. Using the insight from those researchers before me, I strive to further their designs and present relevant information in a design compendium that makes it more useful to those who have an application for the device. This thesis resulted in two novel designs for a PDW. First, a changing radius foot was developed to increase knee flexion upon toe off. The decrease in radius increases joint angular velocity resulting in ramp up. Further investigation of these feet could result in more stable and efficient walking patterns. The other design brought to attention is the planar crossbar mechanism for coupling the inner and outer legs. The crossbar provides a rigid coupling without changing the rotational inertia between the coupled pair about the hip axis.
28

Balance preservation and task prioritization in whole body motion control of humanoid robots / Préservation de l'équilibre et priorisation des tâches dans la commande du mouvement corps entier de robots humanoïdes

Sherikov, Alexander 23 May 2016 (has links)
Un des plus grands défis dans la commande des robots est de combler l'écart entre la capacité de mouvement de l'humain et des robots humanoïdes. La difficulté réside dans la complexité des systèmes dynamiques représentant les robots humanoïdes: la non linéarité, le sous-actionnement, le comportement non-lisse en raison de collisions et de frottement, le nombre élevé de degrés de liberté. De plus, les robots humanoïdes sont censés opérer dans des environnements non-déterministes, qui exigent une commande temps réel avancée.L'approche qui prévaut actuellement pour faire face à ces difficultés est d'imposer diverses restrictions sur les mouvements et d'employer des modèles approximatifs des robots. Dans cette thèse, nous suivons la même ligne de recherche et proposons une nouvelle approche pour la conception de contrôleurs corps entier qui préservent l'équilibre. L'idée principale est de tirer parti des avantages des modèles approximatifs et de corps entier en les mélangeant dans un seul problème de contrôle prédictif avec des objectifs strictement hiérarchisés.La préservation de l'équilibre est l'une des principales préoccupations dans la commande des robots humanoïdes. Des recherches antérieures ont déjà établi que l'anticipation des mouvements est essentiel à cet effet. Nous préconisons que l'anticipation est utile dans ce sens comme un moyen de maintenir la capturabilité du mouvement, i.e., la capacité de s'arrêter. Nous soulignons que capturabilité des mouvements prévus peut être imposée avec des contraintes appropriées. Dans la pratique, il est fréquent d'anticiper les mouvements du robot à l'aide de modèles approximatifs afin de réduire l'effort de calcul, par conséquent, un contrôleur séparé de mouvement du corps entier est nécessaire pour le suivi. Au lieu de cela, nous proposons d'introduire l'anticipation avec un modèle approximatif directement dans le contrôleur corps entier. En conséquence, les mouvements du corps entier générés respectent les contraintes de capturabilité et les mouvements anticipes du modèle approximatif prennent en compte les contraintes et les tâches désirées pour le corps entier. Nous posons nos contrôleurs du mouvement du corps entier comme des problèmes d'optimisation avec des objectifs strictement hiérarchisés. Bien que cet ordre de priorité soit commun dans la littérature, nous croyons qu'il est souvent mal exploité.Par conséquent, nous proposons plusieurs exemples de contrôleurs, où la hiérarchisation est utile et nécessaire pour atteindre les comportements souhaités. Nous évaluons nos contrôleurs dans deux scénarios simulés, où la tâche du corps entier du robot influence la marche et le robot exploite éventuellement un contact avec la main pour maintenir son équilibre en étant debout. / One of the greatest challenges in robot control is closing the gap between themotion capabilities of humans and humanoid robots. The difficulty lies in thecomplexity of the dynamical systems representing the said robots: theirnonlinearity, underactuation, discrete behavior due to collisions and friction,high number of degrees of freedom. Moreover, humanoid robots are supposed tooperate in non-deterministic environments, which require advanced real timecontrol. The currently prevailing approach to coping with these difficulties isto impose various limitations on the motions and employ approximate models ofthe robots. In this thesis, we follow the same line of research and propose anew approach to the design of balance preserving whole body motion controllers.The key idea is to leverage the advantages of whole body and approximate modelsby mixing them within a single predictive control problem with strictlyprioritized objectives.Balance preservation is one of the primary concerns in the control of humanoidrobots. Previous research has already established that anticipation of motionsis crucial for this purpose. We advocate that anticipation is helpful in thissense as a way to maintain capturability of the motion, i.e., the ability tostop. We stress that capturability of anticipated motions can be enforced withappropriate constraints. In practice, it is common to anticipate motions usingapproximate models in order to reduce computational effort, hence, a separatewhole body motion controller is needed for tracking. Instead, we propose tointroduce anticipation with an approximate model into the whole body motioncontroller. As a result, the generated whole body motions respect thecapturability constraints and the anticipated motions of an approximate modeltake into account whole body constraints and tasks. We pose our whole bodymotion controllers as optimization problems with strictly prioritizedobjectives. Though such prioritization is common in the literature, we believethat it is often not properly exploited. We, therefore, propose severalexamples of controllers, where prioritization is useful and necessary toachieve desired behaviors. We evaluate our controllers in two simulatedscenarios, where a whole body task influences walking motions of the robot andthe robot optionally exploits a hand contact to maintain balance whilestanding.
29

Determinação da força peso, a partir dos impactos de pisadas, utilizando um sensor piezoeletrico / Calculation of weight from step impacts, using a piezoelectric sensor

Nadalin, Everton Zaccaria 26 October 2007 (has links)
Orientador: Carlos Alberto dos Reis Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-10T09:10:45Z (GMT). No. of bitstreams: 1 Nadalin_EvertonZaccaria_M.pdf: 2191420 bytes, checksum: 38decb6d182261bd5e5fc2df03ad1b9a (MD5) Previous issue date: 2007 / Resumo: Este trabalho está relacionado com o problema da pesagem de um bovino criado em campo aberto, não confinado, destinado ao corte. O conhecimento da evolução contínua do peso do animal é de grande importância neste ramo de negócios e uma solução tecnicamente satisfatória, de custo aceitável e de tecnologia proprietária, certamente representa uma significativa contribuição ao Brasil. Uma solução idealizada, que é a meta maior do projeto em que este trabalho se enquadra, prevê o uso de um dispositivo instalado nas patas do animal, contendo um sensor de pressão ou de impacto e uma unidade eletrônica local que condiciona, digitaliza e armazena os sinais do sensor. Além disto, a unidade eletrônica transmite estes dados através de uma rede de comunicação de dados sem fio e de baixo consumo de energia para centrais de coleta e processamento estrategicamente situadas na área em que o gado se desenvolve. Tal sistema viabiliza, deste modo, acumular no tempo as informações de cada pisada de cada animal. O sinal produzido por um sensor em conseqüência do impacto de cada pisada é influenciado por diversos parâmetros, dentre os quais o peso do animal. Sendo assim, é impossível estabelecer uma relação direta e exclusiva entre o sinal do sensor e o peso. Entretanto, os valores acumulados destes sinais descrevem uma função de múltiplas variáveis que pode ser tratada juntamente com algumas informações complementares sobre o ambiente, buscando-se o isolamento da variável peso. Para isto, uma abordagem adequada prevê o desenvolvimento ou adoção de um modelo do mecanismo de movimentação do animal e o tratamento numérico dos dados acumulados aplicando filtragens e buscas de correlações. Trata-se, portanto, de uma solução de natureza multidisciplinar, que exige uma aliança de conhecimentos complementares para a sua realização. Coube ao presente trabalho, desenvolvido no âmbito da engenharia eletrônica, a implementação de uma etapa preliminar e necessária que consiste de um sistema de caracterização de pisadas constituído de um conjunto de sensores piezoelétricos, uma interface que permite a transferência dos dados destes sensores a um computador e um ambiente de software através do qual foram testados algoritmos para a verificação de correlação entre os sinais associados às pisadas e o peso do agente. São frutos deste trabalho um sistema de coleta automática dos sinais de pisadas, que permitiu a captura de sinais com sensores instalados tanto numa plataforma fixa como num sapato tênis, e um estudo comparativo dos resultados obtidos de tratamentos numéricos distintos aplicados aos dados experimentais / Abstract: This work deals with the problem of weighting non-confined cattle raised in open field for meat production. The knowledge of the continuous weight change of the animal is of great importance in this business field. Therefore, a technically satisfactory solution, with acceptable price and customized technology, certainly represents a significant contribution to Brazil. The idealized solution, which is the major goal to be pursued by the project in which this work takes part, considers the use of a device placed into the animal¿s hooves. It would contain a pressure or impact sensor and a local electronic unit, which conditions, digitizes and stores the signals received from the sensor. The electronic unit also transmits this data through a low-energy wireless communication network to reception and processing stations placed strategically around the area where the cattle raises. Such a system enables accumulating data about the steps of each animal throughout time. Several parameters, including the animal¿s weight, influence the signal produced by a sensor as a consequence to the impact of a step. Therefore, it is impossible to establish a direct and exclusive relation between the signal given by the sensor and the weight. Nevertheless, the accumulated data of these signals describe a multiple variable function that can be treated together with some complementary information about the environment, seeking the isolation of the weight variable. An adequate approach predicts the development or use of a model of the animal¿s locomotion mechanism and the numeric treatment of the accumulated data by applying filtering and seeking correlations. The multidisciplinary nature of this solution demands an alliance of complementary knowledge for its accomplishment. This work, developed in the scope of electrical engineering, implemented a necessary and preliminary stage that consists of: a step characterization system, made of a set of piezoelectric sensors, an interface that allows transferring data from the sensors to a computer and a software environment, in which algorithms were tested to verify the correlation between the signals associated to the steps and the agent¿s weight. The main result of this work are a system that performs automatic collecting of steps, which allowed the capture of the signals with sensors installed both on a fixed platform and inside tennis shoes, and the comparative study of the results of different numerical treatments applied to the experimental data / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica
30

The Effects of Kinesiology Tape on Static Postural Control in Individuals with Functional Ankle Instability

Ly, Kien Trung 03 September 2020 (has links)
Functional ankle instability (FAI) is characterized by the recurrent giving way of the ankle and the constant feeling of instability that affects the quality of life of its patients adversely. Kinesiology Tape (KT), differed from the traditional rigid athletic tape, becomes more popular as a new therapeutic tool for injuries management. It is reported to decrease pain, promote blood circulation and natural healing of muscular functioning. However, scientific evidence of KT’s effects on FAI remains very limited. Therefore, the purpose of the present study was to investigate if applying KT on the unstable ankle may improve static postural control in individuals with FAI. Twenty young adults with FAI performed a series of static quiet bipedal and unipedal stances on a force platform. Postural control was assessed by four measures derived from the centre of pressure (COP) data: 95% Confidence ellipse of total displacements (area), standard deviation of displacements (SD), mean velocity and mean power frequency (MPF). Measurements were taken at three different times: baseline or no tape, immediately after the application of KT on the unstable ankle, and 24 hours after the taping application with the tape remaining on the ankle. Results revealed only minor changes in mean velocity and MPF in unipedal stances immediately after KT application. However, the overall results indicated statistically insignificant improvements in postural control performance neither immediately after KT application nor after 24 hours. In conclusion, our results suggest that the use of KT did not affect bipedal and unipedal stances of individuals with functional ankle instability.

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