Orientador: Sergio Augusto Cunha / Banca: Lilian Teresa Bucken Gobbi / Banca: René Brenzikofer / Resumo: O futsal tem sido estudado sob o enfoque de diversos temas e olhares. Neste trabalho o futsal foi analisado através da perspectiva da Biomecânica. O objetivo do estudo foi descrever o chute executado com o membro dominante e com o membro não dominante realizado com a bola parada e em deslocamento no futsal. Participaram dez jogadores da equipe de futsal adulta da UNESP Campus Rio Claro, os quais realizaram dez chutes com a bola em deslocamento e dez chutes com a bola parada, sendo cinco chutes com cada membro para cada situação. Os chutes foram realizados com o dorso do pé, procurando empregar velocidade máxima a bola e objetivando acertá-la em um alvo de 1m2 colocado no centro do gol. Os movimentos foram filmados por sete câmeras posicionadas de modo que enfocassem os marcadores passivos colocados em ambos os membros inferiores dos participantes. As imagens destes chutes foram transferidas para o computador e trabalhadas no software DVIDEOW, sendo realizado os processos de desentrelaçamento, sincronização, medição e reconstrução 3D. Após isso, ocorreu a suavização das através função LOESS e através do método de Euler foram calculados os ângulos de rotação das articulações. Para isso, foi definida uma base ortonormal associada a cada segmento corporal através dos versores i, j e k. A velocidade angular foi calculada através da derivada dos ângulos em função do tempo para cada articulação. Para o desempenho foram avaliados os acertos e erros do alvo. Para a velocidade da bola e velocidade do pé do membro de chute foi realizada, em função do tempo, uma regressão linear de primeiro grau para os eixos X e Y e uma regressão linear do segundo grau para o eixo Z, sendo a xiii velocidade média da bola e do pé calculada a partir da distância percorrida dividida pelo tempo de percurso...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The futsal has been studied under the focus of several themes. This work analyzed the futsal in the Biomechanics perspective. The aim of this study was to describe the kick with the dominant and non-dominant limb performed with the stationary and in displacement ball in futsal. Ten players participated of the UNESP - Campus Rio Claro futsal adult team. They performed ten kicks with the ball in displacement and ten kicks with the stationary ball (five kicks with each limb for each situation). The kicks performed were the maximal instep kicks and should hit a 1 x 1 m target positioned in the goal centre. The movements were recorded by six cameras with focus in the passive markers placed in the participants inferior limbs. The kicking images were transferred to the computer and worked in the DVIDEOW software. The extracted files of this software were smoothed through the LOESS function and joints rotation angles were calculated by the Euler method. For that, it was defined the ortonormal base associated to each corporal segment through i, j and k versores. The angular speed was calculated through angles derived for the time and for each joint. The kicks performance was analyzed through the observation of the success or failure of hitting in the target. For the ball and kick limb foot speed were carried through, in function of the time, a linear regression of first degree for X and Y axles and a linear regression of second degree for Z axle. Then, the average ball and foot speed was calculated from the covered distance divided for the time for the data parameterized in each kick. The results for the angular kinematic standard and angular speed showed significant differences among dominant and not dominant kick and support limb. For the kick type small differences was 126 detected mainly at the moment of contact with the ball...(Complete abstract click eletronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:22:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-05-09Bitstream added on 2014-06-13T19:49:11Z : No. of bitstreams: 1 barbieri_fa_me_rcla.pdf: 2262727 bytes, checksum: 09a4c61c625a0d2da558ac1e8cb96947 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O futsal tem sido estudado sob o enfoque de diversos temas e olhares. Neste trabalho o futsal foi analisado através da perspectiva da Biomecânica. O objetivo do estudo foi descrever o chute executado com o membro dominante e com o membro não dominante realizado com a bola parada e em deslocamento no futsal. Participaram dez jogadores da equipe de futsal adulta da UNESP Campus Rio Claro, os quais realizaram dez chutes com a bola em deslocamento e dez chutes com a bola parada, sendo cinco chutes com cada membro para cada situação. Os chutes foram realizados com o dorso do pé, procurando empregar velocidade máxima a bola e objetivando acertá-la em um alvo de 1m2 colocado no centro do gol. Os movimentos foram filmados por sete câmeras posicionadas de modo que enfocassem os marcadores passivos colocados em ambos os membros inferiores dos participantes. As imagens destes chutes foram transferidas para o computador e trabalhadas no software DVIDEOW, sendo realizado os processos de desentrelaçamento, sincronização, medição e reconstrução 3D. Após isso, ocorreu a suavização das através função LOESS e através do método de Euler foram calculados os ângulos de rotação das articulações. Para isso, foi definida uma base ortonormal associada a cada segmento corporal através dos versores i, j e k. A velocidade angular foi calculada através da derivada dos ângulos em função do tempo para cada articulação. Para o desempenho foram avaliados os acertos e erros do alvo. Para a velocidade da bola e velocidade do pé do membro de chute foi realizada, em função do tempo, uma regressão linear de primeiro grau para os eixos X e Y e uma regressão linear do segundo grau para o eixo Z, sendo a xiii velocidade média da bola e do pé calculada a partir da distância percorrida dividida pelo tempo de percurso... / The futsal has been studied under the focus of several themes. This work analyzed the futsal in the Biomechanics perspective. The aim of this study was to describe the kick with the dominant and non-dominant limb performed with the stationary and in displacement ball in futsal. Ten players participated of the UNESP - Campus Rio Claro futsal adult team. They performed ten kicks with the ball in displacement and ten kicks with the stationary ball (five kicks with each limb for each situation). The kicks performed were the maximal instep kicks and should hit a 1 x 1 m target positioned in the goal centre. The movements were recorded by six cameras with focus in the passive markers placed in the participants inferior limbs. The kicking images were transferred to the computer and worked in the DVIDEOW software. The extracted files of this software were smoothed through the LOESS function and joints rotation angles were calculated by the Euler method. For that, it was defined the ortonormal base associated to each corporal segment through i, j and k versores. The angular speed was calculated through angles derived for the time and for each joint. The kicks performance was analyzed through the observation of the success or failure of hitting in the target. For the ball and kick limb foot speed were carried through, in function of the time, a linear regression of first degree for X and Y axles and a linear regression of second degree for Z axle. Then, the average ball and foot speed was calculated from the covered distance divided for the time for the data parameterized in each kick. The results for the angular kinematic standard and angular speed showed significant differences among dominant and not dominant kick and support limb. For the kick type small differences was 126 detected mainly at the moment of contact with the ball...(Complete abstract click eletronic access below)

This thesis deals with principles of measuring of acceleration with commercially available accelerometers and theoretical analyses of measuring of angular speed of rotational motion. Then the proposition of application’s connection controlled by microprocessor and software solution with implementation of serial communication interface is described. The function of the apparatus is examined with experimental measuring and elaborated protocol.

Most drill wear monitoring research found in the literature is based on conventional vibration technologies. However, these conventional approaches still have not attracted real interest from manufacturers for multiples of reasons: some of these techniques are not practical and use complicated Tool Condition Monitoring (TCM) systems with less value in industry. In addition, they are also prone to give spurious drill deterioration warnings in industrial environments. Therefore, drills are normally replaced at estimated preset intervals, sometimes long before they are worn or by expertise judgment. Two of the great problems in the implementation of these systems in drilling are: the poor signal-to-noise ratio and the lack of system-made sensors for drilling, as is prevalent in machining operations with straight edge cutters. In order to overcome the noise problems, many researchers recommend advanced and sophisticated signal processing while the work of Rehorn et al. (2005) advises the following possibilities to deal with the lack of commercial system-made sensors:  Some research should be directed towards developing some form of instrumented tool for drill operations.  Since the use of custom-made sensors is being ignored in drilling operations, effort should be focused on intelligent or innovative use of available sensor technology. It is expected that the latter could minimize implementation problems and allows an optimal drill utilization rate by means of modern and smart sensors. In addition to the accelerometer sensor commonly used in conventional methods, this work has considered two other sensor-based methods to monitor the drill wear indirectly. These methods entail the use of an instrumented drill with strain gauges to measure the torque and the use of an encoder to measure the Instantaneous Angular Speed (IAS). The signals from these sensors were analyzed using signal processing techniques such as, statistical parameters, Fast Fourier Transform (FFT), and a ii preliminary Time-Frequency (TF) analysis. A preliminary investigation has revealed that the use of a Regression Analysis (RA) based on a higher order polynomial function can very well follow and give prognosis of the development of the monitored parameters. The experimental investigation has revealed that all the above monitoring systems are sensitive to the deterioration of the drill condition. This work is however particularly concerned with the use of IAS on the spindle of the drill, compared to conventional monitoring systems for drill condition monitoring. This comparison reveals that the IAS approach can generate diagnostic information similar to vibration and torque measurements, without some of the instrumentation complications. This similitude seems to be logical, as it is well known that the increase of friction between the drill and workpiece due to wear increase the torque and consequently it should reduce or at least affect the spindle rotational speed. However, the use of a drill instrumented with a strain gauge is not practical, because of the inconvenience it causes on production machines. By contrast, the IAS could be measured quite easily by means of an encoder, a tachometer or some other smart rotational speed sensors. Thus, one could take advantage of advanced techniques in digital time interval analysis applied to a carrier signal from a multiple pulse per revolution encoder on the rotating shaft, to improve the analysis of chain pulses. As it will be shown in this dissertation, the encoder resolution does not sensibly affect the analysis. Therefore, one can easily replace encoders by any smart transducers that have become more popular in rotating machinery. Consequently, a non-contact transducer for example could effectively be used in on-line drill condition monitoring such as the use of lasers or time passage encoder-based systems. This work has gained from previous research performed in Tool Condition Monitoring TCM, and presents a sensor that is already available in the arsenal of sensors and could be an open door for a practical and reliable sensor in automated drilling. iii In conclusion, this dissertation strives to answer the following question: Which one of these methods could challenge the need from manufacturers by monitoring and diagnosing drill condition in a practical and reliable manner? Past research has sufficiently proved the weakness of conventional technologies in industry despite good results in the laboratory. In addition, delayed diagnosis due to time-consuming data processing is not beneficial for automated drilling, especially when the drill wears rapidly at the end of its life. No advanced signal processing is required for the proposed technique, as satisfactory results are obtained using common time domain signal processing methods. The recommended monitoring choice will definitely depend on the sensor that is practical and reliable in industry. / Dissertation (MEng)--University of Pretoria, 2012. / gm2013 / Mechanical and Aeronautical Engineering / MEng / Unrestricted

Dans l’industrie de fabrication mécanique et notamment pour l’utilisation des centres d’usinage haute vitesse, la connaissance des propriétés dynamiques du système broche-outil-pièce en opération est d’une grande importance. L’accroissement des performances des machines-outils et des outils de coupe a œuvré au développement de ce procédé compétitif. D’innombrables travaux ont été menés pour accroître les performances et les remarquables avancées dans les matériaux, les revêtements des outils coupants et les lubrifiants ont permis d’accroître considérablement les vitesses de coupe tout en améliorant la qualité de la surface usinée. Cependant, l’utilisation rationnelle de cette technologie est encore fortement pénalisée par les lacunes dans la connaissance de la coupe, que ce soit au niveau microscopique des interactions fines entre l’outil et la matière coupée, aussi bien qu’au niveau macroscopique intégrant le comportement de la cellule élémentaire d’usinage, si bien que le comportement dynamique en coupe garde encore une grande part de questionnement et exige de l’utilisateur un bon niveau de savoir-faire et parfois d’empirisme pour exploiter au mieux les capacités des moyens de production. Le fonctionnement des machines d’usinage engendre des vibrations qui sont souvent la cause des dysfonctionnements et accélère l’usure des composantes mécaniques (roulements) et outils. Ces vibrations sont une image des efforts internes des systèmes, d’où l’intérêt d’analyser les grandeurs mécaniques vibratoires telle que la vitesse ou l’accélération vibratoire. Ces outils sont indispensables pour une maintenance moderne dont l’objectif est de réduire les coûts liés aux pannes / In machining field, chatter phenomenon takes a lot of interest because manufacturing enterprises are turning to the automation system and the development of reliable and robust monitoring system to provide increased productivity, improved part quality and reduced costs. Chatter occurrence has several negatives effects: a) Poor surface quality, b) Unacceptable inaccuracy, c) Excessive noise, d) Machine tool damage, e) Reduced material removal rate, f) Increase costs in terms of production time, g) Waste of material, h) Environmental impact in terms of materials and energy. Moreover, chatter monitoring is not an easy task for various reasons. Firstly, the non linearity of machining processes and the time-varying of systems complicate this task. Secondly, the sensitivity and the dependency of acquired signals from sensors on different factors, such as machining condition, cutting tool geometry and workpiece material. Thirdly, at high rotating speeds, the gyroscopic effects on the spindle dynamics in addition to the centrifugal force on the bearings and thermal effects become more relevant thus affecting the stability of the system. For these reasons, demands for an advanced automatic chatter detection and monitoring system for optimizing and controlling machining processes becomes a topic of enormous interest. Several researches in this field are performed. Advanced monitoring and detection methods are developed mostly relying on time, frequency and time-frequency analysis. In order to detect chatter in milling centers, three new methods are studied and developed using advanced techniques of signal processing and exploiting cyclostationarity property of signals acquired

<p>Disertacija istražuje primenu fleksibilne elektronike za<br />kapacitivne senzore ugla i ugaone brzine tipa apsolutnog i<br />inkrementalnog enkodera cilindrične strukture. Razmatraju se dve<br />strukture, apsolutnog i inkrementalnog enkodera. Izvršena je analiza<br />uticaja mehaničkih nesavršenosti na funkciju kapacitivnosti.<br />Razvijena su dva prototipa kapacitivnih senzora za statičko i<br />dinamičko ispitivanje karakteristika senzora. Razvijena je<br />elektronika za obradu senzora inkrementalnog tipa sa<br />autokalibracijom senzora.</p> / <p>In this thesis a research on application of flexible electronics for capacitive<br />angular position and speed sensors, referred to as absolute and incremental<br />encoders, is done. It considers two structures of absolute and incremental<br />encoder type. An analysis of mechanical inaccuracies influence on a<br />capacitance function is conducted. Two prototypes are developed and used<br />for static and dynamic measurements of capacitive sensor&#39;s characteristics.<br />An electronics front-end for a capacitive two channel incremental encoder with<br />auto-calibration is developed.</p>