The submitted Master’s thesis deals with the general principle of the electric drives’ functioning and with the construction of a synchronous electric motor. A comparison of a linear drive and a rotary drive with rack and pinion system is provided, as well as an overview of common type linear drives. A mathematical model of a rotary synchronous motor, the Clark’s and Park’s transformation and the principle of vector control is explained. A method of the linear parameters’ conversion to the rotary equivalents is demonstrated. A block diagram to motor control is designed. The control quality is tested by various criteria. Lastly, there is a simulation provided on how the changes of motor’s parameters affect the control quality.

The document describe servo drive by B&R and the control algorithms with vector control. There is also mathematic model of synchronous motor, design of control the system of two connected motor and implementation these algorithms in to the PLC and Acopos. The Master’s Thesis contains confrontation of results of real system and ideal model.

Master thesis deals with design and construction of the most widely used engines currently. Overall, it is divided into five chapters, the first chapter deals with constructional features of various three-phase asynchronous motors, the second chapter briefly paid attention to single-phase motors. The next chapter focuses on the specific engine types, which differ from standard induction motors in its design implementation. This is an engine with full rotor, hysteresis, linear and with shaded field. Although asynchronous motors are considered the most reliable machines work in imperfect conditions, it leads to frequent breakdowns. This is covered in chapter four. Based on the findings from previous chapters the fifth chapter includes a preliminary draft of the asynchronous motor with a full rotor. The last chapter is devoted to the measurement on functional models.

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<p>Many daily motor tasks involve the precise control of both force level and motor timing. The neural mechanisms concurrently managing these movement parameters remain unclear, as the dominant focus of previous literature has been to examine each in isolation. As a result, little is understood regarding the contribution of various sensory modalities to force output and interval production in sequential motor tasks. This thesis uses a sequential force production task to investigate the roles of visual and somatosensory feedback in the timed control of force. In Chapter 2 we find that removal of visual force feedback resulted in specific force output errors, but leaves motor timing behavior relatively unaffected according to predictions of the two-level timing model by Wing and Kristofferson (1973). In Chapter 3, we show that force output errors exhibited in the absence of a visual reference may be related to the processing of reafferent somatosensation from self-generated force pulses. The results of Chapter 4 reveal evidence that force errors exhibited following visual feedback removal are consistent with a shift in the perceived magnitude of force output and that the direction of error may be determined by prior task constraints. In Chapter 5 we find evidence of effector-specificity in the processing of and compensation for reafferent somatosensation. Lastly, in Chapter 6 we find that the interplay between audition and somatosensation in the control of sound level by the vocal effectors resembles that which is observed between vision and somatosensation in the control of force by the distal effectors.</p> / Doctor of Philosophy (PhD)

The use of mental practice to facilitate the acquisition of a motor skill was investigated. A transfer design was used to determine if the facilitation of mirror tracing performance could be attributed to learning. Following two trials on the mirror trace subjects performed either mental practice, a reading task, an attentional focus task, or massed practice. Subjects then performed trial 3. Then 52 subjects transferred to the nonpreferred hand for trials 4 and 5. The remaining subjects continued to trace with the preferred hand for trials 4 and 5. Subjects in the mental practice group traced faster than subjects in the reading task and massed practice groups, although they did not trace significantly faster than the attentional focus group. Mental practice subjects did not make significantly fewer errors than subjects in the other groups. An analysis of the transfer task indicated that the faster tracing by the mental practice group might not have been the result of learning. Females tended to trace faster and make fewer errors than males. / M.S.

A grande aplicação residencial de motores de indução monofásicos é em sistemas de refrigeração doméstica/comercial. O desenvolvimento de motores mais eficientes, associado ao controle de velocidade, fez com que, dentro os mais diversos tipos de motores, o motor síncrono de imã permanente tornasse objeto para a criação de uma metodologia de projeto, construção e realização de ensaios. Assim, para adequar o projeto do motor MSIP para substituição do motor de indução monofásico, foram feitos estudos de como aproveitar as laminações já existentes, através de definições das características básicas do estator e do rotor. O imã permanente a ser utilizado foi definido principalmente em função do custo do material e de suas propriedades magnéticas estarem adequadas à necessidade do projeto. O projeto magnético foi feito para maximizar o fluxo nos dentes, considerando as características construtivas e a curva de trabalho dos imãs. O projeto elétrico, a partir de um circuito equivalente do motor, permitiu explicar as relações de torque, corrente e tensão do motor MSIP, bem como a definição das bobinas do motor, quanto ao espaçamento destas entre as ranhuras, o cálculo do número de espiras e o diâmetro dos fios em função da área permitida pela ranhura da lamina do estator. Com as informações obtidas após o cálculo do motor MSIP, passou-se a construção de um protótipo constituído pelo estator, rotor e um sistema de suporte que permitisse o levantamento dos parâmetros do motor. Os parâmetros necessários foram definidos levando-se em consideração a necessidade para o projetista do conversor elétrico, sendo estes dados utilizados em simulações computacionais para a determinação do projeto do acionador. Com isto, os ensaios do motor MSIP permitiram o levantamento dos seguintes parâmetros: resistência, indutância, curvas de tensão de fase e linha da eletromotriz por velocidade em diversas rotações, momento de inércia e atrito viscoso, concluindo assim a proposta deste trabalho, e finalizando a metodologia para o motor MSIP. / A major residential application of single-phase induction motors is in domestic refrigeration. The development of more efficient motors, associated with speed control, has made that, among the most diverse types of electrical motors, the permanent magnet synchronous machine becomes an object of study for a design, construction and testing methodology. Therefore, to suit the PMSM design to replace the single phase induction motor, studies were made on how to take advantage of existing laminations, through definitions of the basic characteristics of the stator and rotor. The permanent magnet used was defined mainly as a function of the cost of the material and its magnetic properties since they suit the design requirements. PMSM magnetic design was made to maximize the magnetic flow in the slots considering the constructive characteristics and the magnet curve. The electric design, starting from a motor equivalent circuit, allowed to explain torque, current and voltage of the PMSM motor, as well as the definition of the motor windings regarding their filling in the slots, the calculation of coil number and the wire diameter as a function of the area allowed by the stator lamination slot. With the information obtained after the PMSM motor calculation, a prototype construction was initiated consisting of the stator, rotor and a support system to allow determining the motor parameters. The required parameters were defined taking into account the need the designer had of an electronic drive had. This data was used in computational simulations to determine the electronic driver design. After this, the motor testing allowed to identify the parameters, namely: winding resistance and inductance, various speed curves versus phase to phase and line voltage for back emf´s, moment of inertia and viscous friction, thus completing this work proposal, finalizing the project methodology for PMSM motor.

A grande aplicação residencial de motores de indução monofásicos é em sistemas de refrigeração doméstica/comercial. O desenvolvimento de motores mais eficientes, associado ao controle de velocidade, fez com que, dentro os mais diversos tipos de motores, o motor síncrono de imã permanente tornasse objeto para a criação de uma metodologia de projeto, construção e realização de ensaios. Assim, para adequar o projeto do motor MSIP para substituição do motor de indução monofásico, foram feitos estudos de como aproveitar as laminações já existentes, através de definições das características básicas do estator e do rotor. O imã permanente a ser utilizado foi definido principalmente em função do custo do material e de suas propriedades magnéticas estarem adequadas à necessidade do projeto. O projeto magnético foi feito para maximizar o fluxo nos dentes, considerando as características construtivas e a curva de trabalho dos imãs. O projeto elétrico, a partir de um circuito equivalente do motor, permitiu explicar as relações de torque, corrente e tensão do motor MSIP, bem como a definição das bobinas do motor, quanto ao espaçamento destas entre as ranhuras, o cálculo do número de espiras e o diâmetro dos fios em função da área permitida pela ranhura da lamina do estator. Com as informações obtidas após o cálculo do motor MSIP, passou-se a construção de um protótipo constituído pelo estator, rotor e um sistema de suporte que permitisse o levantamento dos parâmetros do motor. Os parâmetros necessários foram definidos levando-se em consideração a necessidade para o projetista do conversor elétrico, sendo estes dados utilizados em simulações computacionais para a determinação do projeto do acionador. Com isto, os ensaios do motor MSIP permitiram o levantamento dos seguintes parâmetros: resistência, indutância, curvas de tensão de fase e linha da eletromotriz por velocidade em diversas rotações, momento de inércia e atrito viscoso, concluindo assim a proposta deste trabalho, e finalizando a metodologia para o motor MSIP. / A major residential application of single-phase induction motors is in domestic refrigeration. The development of more efficient motors, associated with speed control, has made that, among the most diverse types of electrical motors, the permanent magnet synchronous machine becomes an object of study for a design, construction and testing methodology. Therefore, to suit the PMSM design to replace the single phase induction motor, studies were made on how to take advantage of existing laminations, through definitions of the basic characteristics of the stator and rotor. The permanent magnet used was defined mainly as a function of the cost of the material and its magnetic properties since they suit the design requirements. PMSM magnetic design was made to maximize the magnetic flow in the slots considering the constructive characteristics and the magnet curve. The electric design, starting from a motor equivalent circuit, allowed to explain torque, current and voltage of the PMSM motor, as well as the definition of the motor windings regarding their filling in the slots, the calculation of coil number and the wire diameter as a function of the area allowed by the stator lamination slot. With the information obtained after the PMSM motor calculation, a prototype construction was initiated consisting of the stator, rotor and a support system to allow determining the motor parameters. The required parameters were defined taking into account the need the designer had of an electronic drive had. This data was used in computational simulations to determine the electronic driver design. After this, the motor testing allowed to identify the parameters, namely: winding resistance and inductance, various speed curves versus phase to phase and line voltage for back emf´s, moment of inertia and viscous friction, thus completing this work proposal, finalizing the project methodology for PMSM motor.

Sport has become a very competitive business and focus has been placed on reaching ones full potential. Visual involvement in a sport varies according to environmental demands associated with that sport. These environmental demands are matched by a task specific motor response. The primary aim of this study was to determine if visual skills training programmes could produce beneficial performance results for cricket and soccer players. In order to measure the athletic ability of a cricket and soccer player it is important not only to measure the hardware visual skills of the player, but also the player’s hand-eye co-ordination ability and software visual skills. Thus, aspects of the nervous system such as perceptual motor co-ordination, reaction time and anticipation ability should also be measured to get an indication of the player’s performance ability. In this study highly skilled cricket players and highly skilled soccer academy players, who were actively participating at a provincial level of competition, served as subjects. Due to professional reasons, the soccer academy players had to withdraw from this study. The provincial cricket players continued for the duration of the programme. Thus, due to the abovementioned the aim of this study was two fold, to determine whether statistically significant differences exist between the pre and post-training measurements of cricket players on several visual skills tests and secondly to determine whether statistically significant differences exist between the pre-training measurements of cricket and soccer players on the various visual skills measurements. The data of the variables tested were coded in computer format and statistically evaluated. Since the sample is relatively small non-parametric statistics were used to analyse the data. Two different Non-parametric t-tests were used: the Wilcoxon test is the distribution-free analogue of the t-test for related samples and the Mann-Whitney test is the distribution-free alternative to the independent samples t-test and was used for testing the differences between the means of the cricket players and the soccer players. After the initial testing the cricket players participated in an eight-week visual skill and performance skills programme for 60 minutes a day, once a week. The programme included sports vision activities, speed and agility activities and ball skills activities. Hereafter a retest was done. The pre-training and post-training values of the cricket players were recorded and significance of difference was determined by using the Wilcoxon signed-ranks test. The experimental research revealed that the visual skills programme did have a significant influence on most of the tested variables (ball handling skills, co-ordination, visual awareness, eye tracking skills, accuracy, peripheral awareness, pro-action – reaction skills and visual concentration). For some variables that were tested on the experimental group (the cricket players) improvements were found, which indicates that the improvements can be ascribed to the visual skills programme. The results indicated that more than half of the variables tested improved. It can thus be concluded that the hypothesis that was set for this paper has been proven right. Statistics indicated that there was an increase in most of the variables tested (ball handling skills, co-ordination, visual awareness, eye tracking skills, accuracy, peripheral awareness, proaction – reaction skills and visual concentration), which prove then that visual skills training will result in an increase in the players’ visual fields resulting to an increase in the visual skills on and off the cricket fields. Visual skills training programmes are beneficial to competitive sports performance. Copyright / Dissertation (MA)--University of Pretoria, 2009. / Biokinetics, Sport and Leisure Sciences / unrestricted

Given today’s trend with environment being very important, there has been an ongoing attempt in the rotating machine industry to create machines with highest efficiency possible. And so, permanent magnet synchronous machines represent types of machine with very high efficiency and are gradually replacing other machines in many applications. This work deals with familiarization of the properties of permanent magnet synchronous motor as well as typical design choices. The main focus of this work is the design of permanent magnet EC motor and following comparison of results obtained from analytical design and analysis in the RMxprt program. Finally, the results of design methods are compared.