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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.
251

The Effects of Alterations to Upper Limb Inertial Properties on Vertical Point-to-Point Movement

Hongo, Adrian K 01 March 2009 (has links)
Purpose: Several studies have examined intralimb coordination between the shoulder and elbow joints during target-oriented movements. These studies have observed consistent patterns in coordination despite changes in movement variables such as speed, direction, and inertia. Researchers used intersegmental dynamics to quantitatively analyze these patterns between shoulder and elbow joints while systematically changing values of these movement variables. Some studies have examined central nervous system adaptations to inertial changes at the elbow and entire arm during a movement, but none have examined inertial changes to the upper limb. Methods: Five male and five female participants aged 27 to 39 years (mean age = 33 ± 4.3 standard deviation) performed a maximal speed, point-to-point, reversal hand movement in the sagittal plane with and without a 2.2 kg. weight attached to their dominant, right upper arm. To determine the effects of the added mass, dependent t-tests were performed on elbow and shoulder peak muscular torques generated during the reversal region of the movement. Results: A significant increase in shoulder joint torque (p < 0.05), a significant increase in movement time (p < 0.05) and a non-significant decrease in elbow muscular torque (p = 0.1074) was shown to achieve the movement objective with the added weight. Conclusions: While future studies may result in more conclusive findings, this study showed a pattern of increased shoulder torque and decreased elbow torque due to the added inertia. Larger shoulder torque was needed to overcome the added inertia and move at high speed. As a result of the higher shoulder force, interaction torque at the elbow increased, and a reduction in elbow torque was needed to control the hand path and accurately hit the targets. This pattern supports Bernstein’s proposal that passively arising phenomena (i.e., interaction torque) is exploited during multi-segment movement.
252

Kompaktní měnič pro stejnosměrný motor / Compact inverter for DC motor

Kvapil, Martin January 2013 (has links)
This master thesis deals project and realization of universal transistor converter for power electronics course. For this converter was at the same time designed control circuit and drive circuit. Next part is about the design of compact converter for DC. This converter is controlled by a microprocessor Freescale.
253

Řídicí systém pro dálkovou laserovou spektroskopii / Control system for remote laser-induced breakdown spectroscopy

Petrilak, Michal January 2013 (has links)
The work deals with the design of the control electronics for measuring set-up for elemental composition analysis using remote LIBS techniques. The electronics is designed in modular way for light interchangeability and variability. It consists of several separate plug-ins; each plug-in solves its part of the problem and communicates with others over the I2C bus. The work describes the basic components and concepts; a special care is taken to describe the modules for stepper motors control and for communication with focusing lens from Canon company.
254

Návrh řídicí desky pro BLDC motor / Design of control board for BLDC motor

Zbranek, Petr January 2014 (has links)
In the context of this master’s thesis are solved algorithms and hardware for control BLDC motor. The first was designed algorithm in LabView called "six-step". This algorithm causes a torque ripple, so in the final version was used vector control. It is a sensor control, so was necessary to design a measurement of rotor position. It was solved using a magnetic position sensor. After testing the control algorithm was designed my own hardware for control the BLDC motor. The main control unit was chosen microprocessor MC56F82743, which is designed specifically for BLDC motor control. The microprocessor was programmed in the CodeWarrior development environment, using a JTAF and USB-TAP.
255

Řízení trojfázového asynchronního motoru / Control of three-phase asynchronous motor

Nekvapil, Jan January 2009 (has links)
This theses concern proposal and implementation asynchronous motor control algorithm in the processor DSP56F807 from the manufacturer Freescale. The complex design of applicable control algorithm and suitable interconnection with processor and outer component is solved in this work. Integral part is also choosing of suitable power elements of inverter and sensors.
256

Polohová regulace motoru pomocí 8bit uP / Positional Motion Control by means of 8bit uP

Janda, Petr January 2010 (has links)
This thesis deals with positional control of DC motor Icla D065 of company SIG Positec Automation GmbH with aid of CAN-Bus and CANopen protocol. Individual parts describe general principle and standards of CAN-Bus and international normalized higher-level protocol CANopen for systems control. For control this motor was used microcontroller PIC18F4685 from company Microchip and developmental environment MPLAB® IDE. With used C language was made program for MCU control communication with a motor by support of CANopen protocol and its motion control. The result of this thesis will be used in solution of research project Intelligent Systems in Automation.
257

Descriptive and explanatory tools for human movement and state estimation in humanoid robotics / Elements d'analyse et de description du mouvement humain et estimation d'état d'un robot humanoïde

Bailly, François 10 October 2018 (has links)
Le sujet principal de cette thèse est le mouvement des systèmes anthropomorphes, et plus particulièrement la locomotion bipède des humains et des robots humanoïdes. Pour caractériser et comprendre la locomotion bipède, il est instructif d'en étudier les causes, qui résident dans le contrôle et l'organisation du mouvement, et les conséquences qui en résultent, que sont le mouvement et les interactions physiques avec l'environnement. Concernant les causes, par exemple, quels sont les principes qui régissent l'organisation des ordres moteurs pour élaborer une stratégie de déplacement spécifique ? Puis, quelles grandeurs physiques pouvons-nous calculer pour décrire au mieux le mouvement résultant de ces commandes motrices ? Ces questions sont en partie abordées par la proposition d'une extension mathématique de l'approche du Uncontrolled Manifold au contrôle moteur de tâches dynamiques, puis par la présentation d'un nouveau descripteur de la locomotion anthropomorphe. En lien avec ce travail analytique vient le problème de l'estimation de l'état pour les systèmes anthropomorphes. La difficulté d'un tel problème vient du fait que les mesures apportent un bruit qui n'est pas toujours séparable des données informatives, et que l'état du système n'est pas nécessairement observable. Pour se débarrasser du bruit, des techniques de filtrage classiques peuvent être employées, mais elles sont susceptibles d'altérer le contenu des signaux d'intérêt. Pour faire face à ce problème, nous présentons une méthode récursive, basée sur le filtrage complémentaire, pour estimer la position du centre de masse et la variation du moment cinétique d'un système en contact, deux quantités centrales de la locomotion bipède. Une autre idée pour se débarrasser du bruit de mesure est de réaliser qu'il résulte en une estimation irréaliste de la dynamique du système. En exploitant les équations du mouvement, qui dictent la dynamique temporelle du système, et en estimant une trajectoire plutôt qu'un point unique, nous présentons ensuite une estimation du maximum de vraisemblance en utilisant l'algorithme de programmation différentielle dynamique pour effectuer une estimation optimale de l'état centroidal des systèmes en contact. Finalement, une réflexion pluridisciplinaire est présentée, sur le rôle fonctionnel et computationnel joué par la tête chez les animaux. La pertinence de son utilisation en robotique mobile y est discutée, pour l'estimation d'état et la perception multisensorielle. / The substantive subject of this thesis is the motion of anthropomorphic systems, and more particularly the bipedal locomotion of humans and humanoid robots. To characterize and understand bipedal locomotion, it is instructive to study its motor causes and its resulting physical consequences, namely, the interactions with the environment. Concerning the causes, for instance, what are the principles that govern the organization of motor orders in humans for elaborating a specific displacement strategy? And then, which physical quantities can we compute for best describing the motion resulting from these motor orders ? These questions are in part addressed by the proposal of a mathematical extension of the Uncontrolled Manifold approach for the motor control of dynamic tasks and through the presentation of a new descriptor of anthropomorphic locomotion. In connection with this analytical work, comes the problem of state estimation in anthropomorphic systems. The difficulty of such a problem comes from the fact that the measurements carry noise which is not always separable from the informative data, and that the state of the system is not necessarily observable. To get rid of the noise, classical filtering techniques can be employed but they are likely to distort the signals. To cope with this issue, we present a recursive method, based on complementary filtering, to estimate the position of the center of mass and the angular momentum variation of the human body, two central quantities of human locomotion. Another idea to get rid of the measurements noise is to acknowledge the fact that it results in an unrealistic estimation of the motion dynamics. By exploiting the equations of motion, which dictate the temporal dynamics of the system, and by estimating a trajectory versus a single point, we then present maximum likelihood estimation using the dynamic differential programming algorithm to perform optimal centroidal state estimation for systems in contact. Finally, a multidisciplinary reflection on the functional and computational role played by the head in animals is presented. The relevance of using this solution in mobile robotics is discussed, particularly for state estimation and multisensory perception.
258

Adaptations to postural and manual control during tool use

Joshua James Liddy (8803229) 07 May 2020 (has links)
<p>Tool use is an important area of research in psychology, neurophysiology, and motor behavior because it provides insights into the organization of perception, cognition, and action. Tool use research has traditionally focused on the neural structures or cognitive processes that contribute to body-tool integration, while there has been comparatively little interest in motor control. When tool use actions are studied, adaptations have mainly been examined at the level of manual control, while postural control and multi-segment coordination have received less attention. Examining these components of behavior in the context of tool use is vital for developing a better understanding of how humans integrate tools into goal-directed actions.</p><p>The goals of this dissertation were to 1) characterize adaptations to postural control over time when performing a manual task with a tool under different levels of postural constraint and determine their relation to manual task performance, 2) examine postural-manual coupling under different levels of postural constraint during tool use, and 3) determine how multi-segment coordination supports postural stability and suprapostural task performance under different levels of postural constraint during tool use. To address these questions, we adopted a sensorimotor adaptation paradigm to examine postural-manual control and multi-segment coordination before, during, and after an extended bout of tool use.</p>Tool-use adaptations were found to extend beyond the end-effector. Postural control played a crucial role in facilitating improvements in the manual control of tools. Placing constraints on posture interfered with these adaptations, disrupting the coordination of postural-manual behaviors during tool use. However, multi-segment coordination was modified to overcome this challenge and facilitate postural stability and manual performance. These results demonstrate that healthy young adults are capable of flexibly recruiting and exploiting available degrees of freedom in a task-dependent manner the potential challenges associated with integrating tools into movements. This dissertation provides preliminary support for the importance of considering postural control in tool use actions and highlights the utility of examining interactions across multiple levels of motor behavior—postural control, manual control, postural-manual coupling, and multi-segment coordination—to elucidate how tools are integrated into complex, goal-directed behaviors.
259

Tvorba testových baterií pro diagnostiku motorických projevů laterality - vztah mezi mozečkovou dominancí a výkonností horní končetiny / Development of Test Batteries for Diagnostics of Motor Laterality Manifestation - Link between Cerebellar Dominance and Hand Performance

Musálek, Martin January 2012 (has links)
The aim of this study is to contribute to the standardization of the new diagnostic tools assessing the motor manifestations of laterality in adults and children aged 8 to 10 years, both in terms of determining the theoretical concept and the selection of appropriate items, and the verification of structural hypotheses concerning the design of acceptable models, including the diagnostic quality of individual parts of the test battery. Moreover in this study we try to suggest new approach in assessing of motor laterality manifestation by means of relationship between cerebellar dominance and hand performance. The first part of this thesis deals with the concept of laterality, its manifestations and meaning in non-living systems and living organisms. As a human characteristic, laterality is manifested in a variety of functional and structural asymmetries. This part also discusses ways of diagnosing motor manifestations of laterality and the issue of cerebellar dominance, including its reflection in the form of asymmetry of the extinction physiological syndrome of upper limbs. The second part focuses on the process of the standardization study, the statistical method of structural equation modelling, and the actual design of test battery construction. The last part of this thesis presents the results...
260

The rubber hand illusion effectiveness on body ownership induced by self-produced movements : A Meta-Analysis

Brundin, Malin January 2020 (has links)
Body ownership can be studied via the rubber hand illusion (RHI), in which an artificial limb can be perceived as belonging to oneself. In the so-called moving RHI paradigm, both body ownership and sense of agency, induced by self-produced movements, can be investigated. The key question of this approach is whether movements generated by oneself increase the illusion of body ownership. Thus far, the results from moving RHI studies are inconsistent.This has led to uncertainty regarding the influences of the motor control mechanism on body ownership. Therefore, this study will present the first meta-analysis on moving RHI to estimate the illusory effectiveness induced by self-produced movements. A total of 23 experimental comparisons with 821 subjects were included in the meta-analysis. The results showed that the overall illusory effect induced by self-produced movements was superior toits control (e.g., asynchronous active movements) (Hedge’s g = 1.38, p &lt; 0.001). However, due to dissimilarity in results between the studies, the sample size in the meta-analysis may not represent the general population. The subgroup analysis showed that studies using physical hands, such as wooden hands, yielded the largest effect compared to studies using a virtual projected hand or a video recorded image of the participant’s own hands. It can be speculated whether a three-dimensional hand with “realness” has an illusory advantage compared to hands presented in virtual or video image settings. Future studies need to apply aunified framework, particularly in experimental setups and measurements. This would obtain consistent results of the strength of the illusion within the moving RHI paradigm.

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