nÃo hà / Este trabalho apresenta a aplicaÃÃo do algoritmo de OtimizaÃÃo por Enxame de PartÃculas (PSO â Particle Swarm Optimization) para sintonia Ãtima de controladores associados à regulaÃÃo de tensÃo e ao aumento do amortecimento de geradores sÃncronos utilizados em plantas termelÃtricas de ciclo combinado. Para representaÃÃo matemÃtica do gerador sÃncrono, utiliza-se o modelo linearizado de terceira ordem do sistema mÃquina conectada a uma barra infinita, vÃlido para estudos de estabilidade a pequenos sinais. Os parÃmetros do regulador automÃtico de tensÃo (AVR â Automatic Voltage Regulator) e do estabilizador de sistema de potÃncia (PSS â Power System Stabilizer) sÃo determinados de maneira Ãtima pela ferramenta computacional proposta. Os parÃmetros obtidos para o AVR e PSS sÃo comparados com valores calculados por tÃcnicas de sintonia convencionais, baseadas em aproximaÃÃes das equaÃÃes que descrevem o sistema. Os resultados de simulaÃÃes a variaÃÃes na tensÃo de referÃncia, considerando a anÃlise da resposta temporal do sistema controlado, demonstram que o PSO à uma tÃcnica eficiente na sintonia dos parÃmetros do AVR e PSS, destacando-se sua simplicidade, baixo esforÃo computacional e boa caracterÃsticas de convergÃncia. / This work presents the application of the Particle Swarm Optimization (PSO) algorithm for optimal tuning of controllers associated with voltage regulation and damping enhancement of synchronous generators used in combined cycle power station. For mathematic representation of the synchronous generator, the third order linearized model of a single machine connected to an infinite bus, valid for small signal stability studies, is used. The Automatic Voltage Regulator (AVR) and Power System Stabilizer (PSS) parameters are optimally determined by the proposed computational tool. The parameters obtained for AVR and PSS are compared with values calculated by conventional tuning techniques based on approximations of the equations that describe the system. The simulations results to reference voltage disturbances, considering the time response analysis of the controlled system, show that PSO is an efficient technique in the tuning of AVR and PSS parameters, with emphasis on its simplicity, low computational effort and good convergence characteristics.

The thesis "Judging the influence of constitutional hypermobility on postural stability" focuses on the problem of constitutional hypermobility (CH) and the influence of joint instability on stability mechanisms. The aim of the research was to find out whether there is a difference in stability mechanisms with tested subjects with CH and without it. Furthermore, the research focuses on the influence of mobility techniques on postural stability by the means of chosen tests carried out on Balance Master® System platform. The tested sample includes 14 women aged from 20 to 28, 7 women with constitutional hypermobility and 7 women as a control group. 6 tests were chosen for the measurement on Balance Master® platform. 2 static tests: modified Clinical Test of Sensory Interaction on Balance (mCTSIB), Unilateral Stance (US), and 4 dynamic tests: Limits of Stability (LOS), Rhytmic weight shift (RWS), Step Up Over (SUO) a Forward Lunge (FL). We compared the medians of output values of individual tests. It was assumed that subjects with KH would have significantly worse test results than the control group. Furthermore, it was supposed that the mobilization processes cause stability disturbance on the basis of cancellation of compensational , thus protective block in comparison with KS. Powered by TCPDF (www.tcpdf.org)

This diploma thesis deals with a stability and manoeuvrability of experimental aircraft VUT 001 MARABU. It contains calculation of aerodynamic stability derivations and other data necessary for evaluation of static and dynamic stability. Assessment of convenient autopilot.

Tato práce se zabývá návrhem a realizací palubní elektroniky experimentálního vozidla Car4, dále pak základní programovou výbavou řídicí jednotky a Hardware In the Loop simulačním ověřením funkčnosti řídicí jednotky.

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Low back pain (LBP) remains the most prevalent and costly work-related disability worldwide and is directly associated with "physical" risk factors prevalent in manual material handling (MMH) tasks. Back-support exoskeletons (BSEs) are a promising ergonomic intervention to mitigate LBP risk, by reducing muscular exertion and spine loading. The purpose of this work was to help better understand both the "intended" and "unintended" consequences of BSE use on physical risk factors for LBP, as an essential prerequisite for the safe and effective implementation of this technology in actual workplaces. The first study assessed the effects of using two BSEs on objective and subjective responses during repetitive lifting involving symmetric and asymmetric postures. Wearing both BSEs significantly reduced peak levels of trunk extensor muscle activity and reduced energy expenditure. Such reductions, though, were more pronounced in the symmetric conditions and differed between the two BSEs tested. The second study quantified the assistive torque profiles of two passive BSEs using a computerized dynamometer, with both human subjects and a mannequin. Clear differences in torque magnitudes were evident between the BSEs, though both generated more assistive torques during flexion than extension. The third study estimated the effects of BSE use on lumbosacral compressive and shear forces during repetitive lifting using an optimization-based model. Using both BSEs reduced peak compression and anteroposterior shear forces, but these effects differed between tasks and BSE designs. Reductions in composite measures of trunk muscle activity did not correspond consistently with changes in spine forces when using a BSE. The fourth study quantified the effects of two passive BSEs on trunk stability and movement coordination during repetitive lifting. Some adverse effects on stability were evident for pelvis and thorax movements and coupling of these body segments, suggesting that caution is needed in selecting a BSE for a given MMH task. Overall, we found that the efficacy of BSEs is design- and task-specific. Important safety features of the exoskeletons were also identified, providing insights on their performance boundaries. Overall, the BSEs tested were more effective and safer in tasks closer to the mid-sagittal plane and with moderate degrees of trunk flexion. / Doctor of Philosophy / Low back pain (LBP) remains the most prevalent and costly work-related disability worldwide, and the risk of LBP is related to "physical" risk factors common in manual material handling (MMH) tasks. Back-support exoskeletons (BSEs) are a new ergonomic intervention that may reduce the risk of occupational LBP, by reducing muscular efforts and loads on the spine. For the safe use of BSEs, though, it is critical to better understand both the "intended" and "unintended" consequences of this emerging technology. In this dissertation, such consequences of BSE use were evaluated in the context of repetitive lifting tasks. The first study assessed the efficacy of two BSEs in terms of physical demands during repetitive lifting tasks involving a range of torso bending and twisting. Wearing both BSEs reduced the physical demands on back muscles and decreased energy consumption. Larger reductions, though, were observed in forward bending and such reductions differed between the two BSEs tested. The second study measured the amount of support provided by two BSEs using a new measurement method, which was examined for both human subjects and a mannequin. Clear differences in the BSE support were evident between the BSEs, and both devices generated more support during torso forward bending than returning upright. The third study estimated the effects of BSE use on low back loadings during repetitive lifting using a computational model. Using both BSEs reduced loads on the low back region, though such reductions were task-specific and depended on the BSE design. The fourth study quantified the effects of the BSE use on torso stability and movement patterns during repetitive lifting. Some adverse effects on stability were evident for lower and upper torso, suggesting that caution is needed in selecting a BSE for a given MMH task. Findings from this work show the potential benefits of BSEs for use in MMH tasks, yet such benefits can depend on the BSE design and the MMH task they are used for. Further, BSE use can lead to adverse effects, especially with tasks involving extreme working postures.

Title: Postural stabilization and balance - theoretical background and definitions (literature review) Objectives: The aim of this theses is to investigate the present situation of theoretical background of postural stabilization and balance and find out the differences between both of these phenomenons. The theses should summarize the current literature including the newest studies. Furthermore, it discusses the most used computerized measurements methods for assessing balance and postural control. Methods: The theses has character of literature review. It is divided into several parts. The beginning introduces the theoretical background. The descriptive and analytical chapter discuss the most used computerized measurement methods for assessing balance and postural control. The discussion summarizes the current situation and results of the theses. Results: The total amount of the 104 studies was found, but only 12 of them met the criteria of the theses. Currently the most used methods for assessing balance and postural control are the computerized dynamic posturography and the visual feedback posturography. In the published studies there were found several differences in the methods of posturography. Even, there was revealed ideological diversity in the authors' opinions and disunity in...

Este trabalho aborda as oscilações eletromecânicas de baixa frequência, relativas a modos interáreas, pouco amortecidos, avaliando o seu impacto no desempenho de redes elétricas multi-máquinas com o objetivo de elevar o amortecimento destes modos com equipamentos TCSC. Os locais apropriados para instalação destes equipamentos são escolhidos com a análise dos resíduos de funções de transferência e o ajuste de parâmetros, para o projeto coordenado de controladores, utiliza o método de imposição de polos. O sistema não linear de equações, obtido com a aplicação do método de imposição de polos, supondo coeficientes de amortecimento pré-estabelecidos, é resolvido utilizando-se o método de Newton Raphson. Adicionalmente, avalia-se a possibilidade do método auxiliar na análise de interações entre controladores e identificação de acoplamentos, por meio da análise dos termos que compõem as equações de imposição de polos. / This work deals with low frequency oscillations related to inter-area modes, evaluating their impact on the performance of multi-machine electrical networks with the aim to increase the damping of these modes using TCSC. The best places to install these devices are chosen with the analysis of the residues of transfer functions and the parameter fitting for coordinated application of stabilizers is performed with the pole placement method. The nonlinear system of equations, obtained with the pole placement method, assuming specified damping factors, is solved with the Newton-Raphson method. The method is also used in the analysis of control interaction among stabilizers through the evaluation of individual parcels of the pole placement equations, as an additional feature of the approach.

Este trabalho aborda as oscilações eletromecânicas de baixa frequência, relativas a modos interáreas, pouco amortecidos, avaliando o seu impacto no desempenho de redes elétricas multi-máquinas com o objetivo de elevar o amortecimento destes modos com equipamentos TCSC. Os locais apropriados para instalação destes equipamentos são escolhidos com a análise dos resíduos de funções de transferência e o ajuste de parâmetros, para o projeto coordenado de controladores, utiliza o método de imposição de polos. O sistema não linear de equações, obtido com a aplicação do método de imposição de polos, supondo coeficientes de amortecimento pré-estabelecidos, é resolvido utilizando-se o método de Newton Raphson. Adicionalmente, avalia-se a possibilidade do método auxiliar na análise de interações entre controladores e identificação de acoplamentos, por meio da análise dos termos que compõem as equações de imposição de polos. / This work deals with low frequency oscillations related to inter-area modes, evaluating their impact on the performance of multi-machine electrical networks with the aim to increase the damping of these modes using TCSC. The best places to install these devices are chosen with the analysis of the residues of transfer functions and the parameter fitting for coordinated application of stabilizers is performed with the pole placement method. The nonlinear system of equations, obtained with the pole placement method, assuming specified damping factors, is solved with the Newton-Raphson method. The method is also used in the analysis of control interaction among stabilizers through the evaluation of individual parcels of the pole placement equations, as an additional feature of the approach.

The nonlinear simulation model of an unmanned aerial vehicle (UAV) in MATLAB&reg / /Simulink&reg / environment is developed by taking into consideration all the possible major system components such as actuators, gravity, engine, atmosphere, wind-turbulence models, as well as the aerodynamics components in the 6 DOF equations of motion. Trim and linearization of the developed nonlinear model are accomplished and various related analyses are carried out. The model is validated by comparing with a similar UAV data in terms of open loop dynamic stability characteristics. Using two main approaches / namely, classical and optimal, linear controllers are designed. For the classical approach, Simulink Response Optimization (SRO) tool of MATLAB&reg / /Simulink&reg / is utilized, whereas for the optimal controller approach, linear quadratic (LQ) controller design method is implemented, again by the help of the tools put forth by MATLAB&reg / . The controllers are designed for control of roll, heading, coordinated turn, flight path, pitch, altitude, and airspeed, i.e., for the achievement of all low-level control functions. These linear controllers are integrated into the nonlinear model, by carrying out gain scheduling with respect to airspeed and altitude, controller input linearization regarding the perturbed states and control inputs, and anti integral wind-up scheme regarding the possible wind-up of the integrators in the controller structures. The responses of the nonlinear model controlled with the two controllers are compared based on the military flight control requirements. The advantages and disadvantages of these two frequently used controllers in industry are investigated and discussed. These results are to be evaluated by the designers themselves based on the design criteria of a project that is worked on.