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1
Britten, Mark David. "Torque Controlled Drive for Permanent Magnet Direct Current Brushless Motors." Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/5252.
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This thesis describes the design and implementation of a simple variable speed drive (VSD) based on a brushless direct current (BLDC) machine and discrete logic circuits. A practical VSD was built, capable of operating a BLDC machine in two quadrants, motoring and regenerative braking. The intended applications are electric scooters and electric bicycles, where the recovered energy from braking extends the range of the vehicle. A conceptual four quadrant VSD, suitable for three and four wheelers requiring reverse operation, was designed and tested in simulation. Simplicity was emphasized in this design to help achieve a robust, easy to analyse system. The versatility of multi-function gate integrated circuits (ICs) made them ideal for implementing the commutation logic and keeping the system simple. The BLDC machine has sensors with a resolution of 60 ed to determine rotor position. An electronic commutator or phase switcher module interprets the position signals and produces a switching pattern. This effectively transforms the BLDC machine into a direct current (DC) brushed machine. A synchronous step down converter controls the BLDC machine current with a tolerance band scheme. This module treats the BLDC machine as if it was a DC machine. The leakage inductance of the electric machine is used as the inductive filter element. The unipolar switching scheme used ensures that current flows out of the battery only for motoring operation and into the battery only during regeneration. The current and torque are directly related in a DC brushed machine. The action of an electronic commutator or phase switcher creates that same relationship between torque and current in a BLDC machine. Torque control is achieved in the BLDC machine using a single channel current controller. The phase switcher current is monitored and used to control the duty ratio of the synchronous converter switches. Successful operation of the practical VSD was achieved in two quadrants: forwards motoring and forwards regenerating. The maximum tested power outputs were 236W in motoring mode and 158W in regenerating mode. The output torque could be smoothly controlled from a positive to a negative value. iv v Simulation of the conceptual four quadrant design was successful in all the motoring, generating and active braking zones. The required manipulation of logic signals to achieve this type of operation was done automatically while the machine was running. The resulting output torque is smoothly controlled in all of the operating zones. Commutation at certain speeds and torques are handled better by some topologies than others. Some current sensing strategies adversely affect instantaneous phase currents under certain conditions. The final design chose the method where phase currents experience no overshoot, minimizing component stress. The battery, or energy storage system, used in verifying the operation of the VSD in the practical electric bicycle was found to be the most limiting component. In regenerating mode, the low charge acceptance rate of the battery reduced the maximum retarding torque and energy recovery rate.
2
Miller, Joel Christopher. "Modulating dynamic stiffness of a direct-drive brushless linear DC motor." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/16103.
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Hamann, Franz, and Gustavo Mesones. "Development of a hybrid system for automatic identification of brushed direct current motors." Institute of Electrical and Electronics Engineers Inc, 2020. http://hdl.handle.net/10757/656635.
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El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.This work proposes a low-cost hybrid hardware and software system that, through a set of methods and nested while loop fitting algorithms, allows to automatically identify the electrical and mechanical parameters of a brushed direct current motor. The aim is to facilitate a tool that contributes to the development of motion control projects in which this type of actuator is used, automating and speeding up the identification process of the motor system aiming to reach 98% accuracy, in order to guarantee a good electrical and mechanical parameter estimates for the brushed direct current motor. To achieve the objective, a platform was developed consisting of a main interface programmed in Matlab and a data acquisition hardware based on a single-phase incremental optical encoder, an H-bridge, an optocoupler circuit, and a C language-programmed DSPIC30F2010. Both parts of the platform are interconnected through the authors' own serial communication protocol.
4
Ghosh, Ramit. "Sensorless starting of a brushless D.C. motor." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43403.
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Permanent magnet brushless DC motors that have found wide application in high performance servo drives need absolute rotor position sensors. However, the cost of the position sensor limits the use of brush less DC motors for low performance applications such as automotive and home appliances. A sensorless starting scheme for brushless DC motors is studied in this thesis. A hardware implementation of the starting scheme has been instrumented. The modeling and simulation of the sensorless starting performance of brushless DC motors have been accomplished to gain the insight into the process. The experimental results confirm the theoretical prediction that the permanent magnet brush less DC motor can be started without a position sensor. The experimental setup with individual subsystems are described in detail.
Master of Science
5
Gan, Jinyun, and 干金云. "Design, analysis and control of multiphase flux regulated permanent magnet brushless DC motor drives." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31245304.
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Wang, Zheng, and 王政. "Chaoization and stabilization of electric motor drives and their industrial applications." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40687594.
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Wang, Zheng. "Chaoization and stabilization of electric motor drives and their industrial applications." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40687594.
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Ai, Yong-le. "Novel direct field and torque control of six-phase induction machine with special phase current waveform." Thesis, Link to the online version, 2006. http://hdl.handle.net/10019/489.
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Borojević, Dušan. "Nonlinear algorithms for fast and robust control of electrical drives." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/74723.
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Several new nonlinear algorithms for speed control of electrical drives are developed. They are compared with the algorithms for integral-proportional (I-P) control, sliding mode control (SLM) and adaptive control which uses the torque and parameter observer. To achieve fast and robust response, all algorithms use very large gains.
In a new, variable limit PI (VLPI) control algorithm, integrator windup is completely prevented by using a high gain, "variable dead zone" nonlinearity as a local feedback over the integrator.
Recently proposed soft variable structure (SVS) control, derived by using the Liapunov direct method, is modified so that the algorithm can be implemented with only the output measurements. Proper operation is achieved for any value of the output variable. The new control is very robust, but exhibits a steady state error.
Two versions of the adaptive PI (API) control algorithm are developed that have fast and robust transient response with zero steady state error. The SVS API version operates similarly as the modified SVS control, but does not have its drawbacks. The SLM API version operates like the SLM control during large transients, and like VLPI control when close to the steady state. The local stability of the control is proved using the "small gain theorem". Its global behavior is analyzed by describing functions.
Very good operation of the SVS API speed control within the proportional position loop is demonstrated. Faster transient response is achieved by implementing the SLM adaptive proportional control in the position loop. The operation is the same as the operation of the SLM API control in the speed loop.
Similarity between modified SVS control, and classical adaptive algorithms is shown. API control, All the algorithms are simulated and compared for twofold and tenfold changes in plant parameters. The experimental verification of the results for I-P control, SLM control, and modified SVS control, are presented.
Theory of the new algorithms is general, such that the results are applicable to any SISO plant that can be stabilized.Ph. D.
10
Jenkins, James Scott. "Operation of a brushless DC drive for application in hybrid electric vehicles." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.mst.edu/thesis/pdf/Thesis_JJenkins_09007dcc8032dbaa.pdf.
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Thesis (M.S.)--University of Missouri--Rolla, 2007.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed October 25, 2007) Includes bibliographical references (p. 61-62).
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Welchko, Brian A. "A high power DC motor controller for an electrical race car using power MOSFETS." Ohio : Ohio University, 1996. http://www.ohiolink.edu/etd/view.cgi?ohiou1239733975.
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Rajagopalan, Satish. "Detection of Rotor and Load Faults in BLDC Motors Operating Under Stationary and Non-Stationary Conditions." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11524.
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Brushless Direct Current (BLDC) motors are one of the motor types rapidly gaining popularity. BLDC motors are being increasingly used in critical high performance industries such as appliances, automotive, aerospace, consumer, medical, industrial automation equipment and instrumentation. Fault detection and condition monitoring of BLDC machines is therefore assuming a new importance. The objective of this research is to advance the field of rotor and load fault diagnosis in BLDC machines operating in a variety of operating conditions ranging from constant speed to continuous transient operation. This objective is addressed as three parts in this research. The first part experimentally characterizes the effects of rotor faults in the stator current and voltage of the BLDC motor. This helps in better understanding the behavior of rotor defects in BLDC motors. The second part develops methods to detect faults in loads coupled to BLDC motors by monitoring the stator current. As most BLDC applications involve non-stationary operating conditions, the diagnosis of rotor faults in non-stationary conditions forms the third and most important part of this research. Several signal processing techniques are reviewed to analyze non-stationary signals. Three new algorithms are proposed that can track and detect rotor faults in non-stationary or transient current signals.
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Smith, Robert Albert. "A performance study of a voltage-fed reluctance synchronous machine." Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/1078.
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Submitted to the Department of Electrical Engineering in Fulfilment of the Requirements for the Magister Technologiae in Electrical Engineering at the Cape Peninsula University of Technology
SUPERVISOR: E. VOSS NOVEMBER 2013The reluctance synchronous machine (RSM) operates on the principle of magnetic reluctance, which is produced through a careful selection of rotor flux barriers and cut-outs. Magnetic reluctivity is the resistance to magnetic flux and can be directly related to the principles of Ohm’s law in electrical circuits. Although reluctance motors have been known for more than 150 years, researchers lost interest when Nikola Tesla’s induction machine (IM) was introduced to industry. Over the last few decades, however, RSMs have shown a lot of potential. They are cheap, robust, reliable, and their rotors can also be used in the stators of IMs. The disadvantage of these machines is an inherently high torque ripple, being the result of its rotor geometry, but the biggest advantage is having a significant reduction in copper losses after the rotor cage has been removed. This advantage drove engineers to investigate, optimise and modify the performance and structure of this machine, which led to the usage of electronic drive systems. The recent advances in technology have allowed researchers to further investigate and modify the design and performance of this special type of machine, with the integration of Finite Element Analysis (FEA) software also making a contribution to the development of the RSM’s current driven systems. The voltage-fed RSM, driven direct-on-line (DOL) from the utility supply, was left in the shadows as the current-fed RSM took reign, but still is, in the author’s opinion, not yet fully analysed. This thesis practically investigates the performance characteristics of the cageless, voltage-fed 3kW RSM in its steady-state operation, under various loads. These performance characteristics are also compared to a RSM driven from a sensorless vector drive (current-fed) to investigate the advantages and disadvantages between the two. Experiments performed on the test bench immediately reveal a limitation to the voltage-fed RSM’s ability to drive higher loads. While the current-fed RSM conveniently reaches 150% of its full-load, the voltage-fed RSM, due to its cageless structure, only reaches 110% of its full-load power. Despite this discovery, the voltage-fed RSM proves to have a lower core loss, harmonic content and torque ripple. Using a FE software package with an integrated source-code, additional parameters such as the dq-axis inductances and currents are also compared and analysed in terms of its reaction to an increase in load. The eddy-current, hysteresis and excess losses are also analysed as well as the harmonic components caused by the geometry of the RSM. For academic purposes, a fair amount of emphasis is placed on the approach to the problem. The preparation for the FE simulation is explained in detail, providing insight into the FE mathematical model as well as parameter acquisition. These parameters include current angle, friction and windage losses, stator resistance, end-winding leakage reactance, core loss and inertia. The results obtained by the FE model are compared to that of the measured results and is found to have an error of only 0.52%. Furthermore, this study attempts to find the feasibility of the voltage-fed RSM’s practicality in modern-day industry. The conclusion is drawn that the voltage-fed RSM could be used as a more elegant alternative to an otherwise over-complicated and over-priced installation.
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TORRES, ALEXANDRE ANDRADE. "DIRECT-CURRENT MOTOR MODELING USING BOND GRAPHS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1998. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=7468@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOREste trabalho tem por objetivo a modelagem do comportamento dinâmico do motor de CC shunt, através da metodologia dos grafos de ligação. Primeiro será feito um levantamento de todos os parâmetros mecânicos, elétricos e magnéticos da máquina. O segundo passo será a obtenção de um grafo de ligação do motor e de suas respectivas equações de estado representativas. Através destas equações e dos parâmetros obtidos em laboratório será montado um modelo de simulação computacional pelo Matlab para verificação do comportamento da máquina desde a partida até o regime permanente, comprovando a veracidade do modelo.
This work has the goal of modeling the dynamic behavior of a CC shunt motor, through the methodology of bond graphs. First all the mechanical, eletrical and magnetic parameters of the machine are measured. The second step will be the development of the motor bond graph and of its respective state equations. Using these equations and the measured parameters a Matlab simulation is set up to verify the transient behavior of yhe machine, checking the truthfulness of the model.
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Knight, Matthew John. "Precision control of a sensorless brushless direct current motor system." Thesis, University of Plymouth, 2002. http://hdl.handle.net/10026.1/2565.
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Sensorless control strategies were first suggested well over a decade ago with the aim of reducing the size, weight and unit cost of electrically actuated servo systems. The resulting algorithms have been successfully applied to the induction and synchronous motor families in applications where control of armature speeds above approximately one hundred revolutions per minute is desired. However, sensorless position control remains problematic. This thesis provides an in depth investigation into sensorless motor control strategies for high precision motion control applications. Specifically, methods of achieving control of position and very low speed thresholds are investigated. The developed grey box identification techniques are shown to perform better than their traditional white or black box counterparts. Further, fuzzy model based sliding mode control is implemented and results demonstrate its improved robustness to certain classes of disturbance. Attempts to reject uncertainty within the developed models using the sliding mode are discussed. Novel controllers, which enhance the performance of the sliding mode are presented. Finally, algorithms that achieve control without a primary feedback sensor are successfully demonstrated. Sensorless position control is achieved with resolutions equivalent to those of existing stepper motor technology. The successful control of armature speeds below sixty revolutions per minute is achieved and problems typically associated with motor starting are circumvented.
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Besson, Pierre. "Using of transcranial direct-current stimulation during motor task for a better outcome." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONT4004/document.
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De tout temps, les humains ont cherché différents moyens pour améliorer leur quotidien. Avec les avancées technologiques actuelles, cette quête s’en trouve facilitée, notamment dans la volonté d’accroître leurs capacités cognitives et/ou motrices. La neuro imagerie permet dorénavant de renseigner les aires cérébrales activées lors de différentes tâches fonctionnelles. Il est aussi possible de moduler l’activité cérébrale en stimulant localement le cerveau avec de faibles courants électriques. Une des techniques les plus répandues à cet effet est appelée tDCS pour transcranial direct current stimulation. Il s’agit en fonction de la polarité du courant induit de moduler à la hausse (stimulation anodale) ou à la baisse (stimulation cathodale) l’excitabilité cortico-spinale en dépolarisant ou en hyperpolarisant la membrane des neurones, respectivement. Malgré une démocratisation grandissante de la neuromodulation via tDCS, les résultats rapportés par la communauté scientifique sont relativement hétérogènes. Les travaux initiés au début des années 2000 sont remis en cause par des résultats actuels faisant état d’une variabilité inter et intra individuelle assez importante. Cette pierre d’achoppement nécessite de développer de nouveaux protocoles d’application de la tDCS. Dans cette thèse, nous avons étudié plusieurs modalités d’application de la tDCS afin d’accroître la persistance des effets neuroplastiques induits et d’augmenter les performances comportementales. Deux études ont été menées afin de révéler dans un premier temps les apports induits par le couplage tâche motrice-tDCS pour ensuite mettre en avant les effets cumulatifs de la répétition de sessions de tâche motrice-tDCS avec pré conditionnement sur la performance motrice. La première étude à travers l’utilisation de la spectroscopie dans le proche infrarouge a permis de rapporter des changements hémodynamiques distincts subséquents au couplage tâche motrice-tDCS par rapport à des protocoles tDCS plus conventionnels. La primauté de l’utilisation concomitante de la tDCS à la tâche motrice a été révélée par la moindre activation du cortex sensorimoteur durant la stimulation ainsi que par une activation cérébrale retardée accrue qui pourrait représenter une réorganisation neuroplastique. La seconde étude s’est intéressée aux effets de la polarité du conditionnement lors de sessions répétées avec comme objectif d’améliorer l’apprentissage et la rétention du système sensorimoteur. Le conditionnement par tDCS était plus propice lors de sessions répétées à engendrer des performances motrices supérieures contrairement à la condition sham. La polarité cathodale engendrait une persistance prolongée. Les premiers résultats de ces travaux de thèse ont permis de défendre l’usage concomitant de la tDCS avec la tâche motrice. De futures recherches sont nécessaires afin d’étudier le transfert de ces résultats dans le monde de l’entraînement ainsi que celui de la réhabilitationHistorically, humans have sought various ways to improve their daily lives. With the current technological advances, this quest is facilitated, especially in the desire to increase their cognitive and / or motor skills. Neuro imagery now makes it possible to inform the areas activated during different functional tasks. Today, it is now possible to modulate brain activity by stimulating the brain locally with weak electrical currents. One of the most common techniques for this purpose is called tDCS for transcranial direct current stimulation. The polarity of the induced current (anodal or cathodal stimulation) allows to modulate upward or downward cortico-spinal excitability by depolarizing or hyperpolarizing the membrane of the neurons, respectively. Despite a growing interest of neuromodulation techniques via tDCS, the results reported by the scientific community are relatively heterogeneous. The work initiated at the beginning of the 2000s is called into question by current results showing a rather large inter and intra variability. This stumbling block requires the development of new protocols for the application of anodal tDCS (atDCS). In this thesis, we were interested in optimizing atDCS protocols in order to increase the persistence of the induced-neuroplastic effects and to increase the behavioral performances. Two studies were carried out in order to first reveal the impact from the motor task/atDCS coupling and then to highlight the cumulative effects of multiple motor-tDCS task sessions with priming atDCS on motor performance. The first study through the use of near infrared spectroscopy allowed to report various hemodynamic changes subsequent to the motor task/atDCS coupling with respect to independent and controlled stimulation protocols. The primacy of the concomitant use of tDCS with the motor task was revealed by the slightest activation of the sensorimotor cortex during stimulation and by an increased delayed cerebral activation which could represent a neuroplastic reorganization. The second study examined the effects of repeated atDCS sessions with anoadal or cathodal tDCS priming in order to improve the learning and retention gains of the sensorimotor system. TDCS priming was more favorable for repeated atDCS sessions to generate higher motor performances contrary to sham. The cathodal polarity produced prolonged persistence. The major findings of this work allow to support the concomitant use of atDCS with the motor task. Future research is needed to study the transfer of these results into the fields of coaching and rehabilitation
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Legha, Daniel. "Predictive maintenance and remote diagnosis for electro-mechanical drives of Very High Speed Trains." Electronic Thesis or Diss., La Rochelle, 2023. http://www.theses.fr/2023LAROS015.
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L'objectif principal de cette recherche est de mettre en œuvre des méthodes de diagnostic prédictif et à distance pour les systèmes d'accessibilité du train, qui sont entraînés par des moteurs à courant continu. Ces systèmes sont les suivants : Les portes intérieures, le gap filler, la porte d'accès des passagers et l'ascenseur. La recherche aborde de multiples équations de maintenance prédictive et de télédiagnostic, telles que : Test de la tension de la courroie, pour tous les types de portes intérieures. Le bon état de la butée d'ouverture de la porte, pour tous les types de portes intérieures. Signature du bon fonctionnement des portes intérieures, à l'aide des signaux enregistrés dans le Big Data, tels que le courant et la tension du moteur, la position de la porte, la vitesse, les capteurs de position, la durée des cycles et d'autres informations contextuelles enregistrées sur le sous-système. Signature du bon fonctionnement du Gap Filler, qui a les mêmes objectifs que la signature du bon fonctionnement des portes intérieures. En ce qui concerne l'aspect théorique, la recherche vise à identifier un ensemble de modes de défaillance sélectionnés sur la base des signaux suivants : Courant du moteur, tension du moteur, position du moteur, vitesse du moteur, capteurs de position et données contextuelles telles que la température, l'inclinaison... La recherche vise à étudier les signaux en régime transitoire et non transitoire, avec et sans capteurs de position dans certains cas, avec une ingénierie des caractéristiques basée sur le domaine temporel, le domaine fréquentiel et le temps-fréquence. En outre, la recherche aborde les techniques d'apprentissage automatique pour la classification des données et des défaillances. L'objectif principal est de travailler sur des techniques basées sur le signal, et si possible, des recherches supplémentaires seront effectuées en utilisant des techniques basées sur le modèleThe main objective of this research is to implement predictive and remote diagnosis solutions for the train’s accessibility systems, which are driven by direct current motors. And these systems are the Internal Doors, the Gap Filler, the Passengers’ Access Door, and the Lift. The research tackles multiple predictive maintenance and remote diagnosis equations, such as: Test of the belt tension, for all the types of Internal Doors. The good condition of the door open stopper, for all types of Internal Doors. Signature of proper operation of Internal Doors, using the Big Data recorded signals such as the motor current, motor voltage, door position, speed, position sensors, cycles’ timings, and other contextual information recorded on the subsystem. Signature of proper operation of Gap Filler, which has the same objectives as the signature of proper operation of Internal Doors...Regarding the academic side, the research aims to identify a set of selected failure modes based on the following signals: Motor current, Motor Voltage, Motor position, Motor speed, Position sensors, and contextual data such as the temperature, the cant/tilt... The research aims to study the signals intransient and non-transient regimes, with and without position sensors in some cases, with features engineering based on the time domain, the frequency domain, and time-frequency. Furthermore, the research tackles Machine Learning techniques for data/failure classification. The main objective is to work on signal-based techniques, and if possible, additional investigation will be done using model-based techniques
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Gidyk, Darryl C. "Modulation of compensation and recovery in a rat model of motor cortex stroke : implications of transcranial direct current stimulation." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Neuroscience, c2011, 2011. http://hdl.handle.net/10133/3236.
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The present thesis examines the effects of transcranial direct current stimulation and
forelimb rehabilitation on motor recovery after stroke in rats. Post-stroke motor outcomes were
quantified using an innovative battery of behavioural tests and high resolution, in vivo
electrophysiology was employed to examine coherence of neural activity between hemispheres.
It was shown that rats that received brain stimulation concurrently with forelimb rehabilitation
displayed functional recovery, whereas rats that received rehabilitation alone partially regained
motor function, but the improvements were not due to restitution of original movement
patterns. Results from electrophysiological recordings showed that rats that received brain
stimulation and rehabilitation regained pre-stroke levels of interhemispheric coherence, but rats
that received rehabilitation alone did not. The present thesis suggests that transcranial direct
current stimulation may be a viable adjunct therapy to increase the efficacy of physical
rehabilitation with regard to post-stroke motor outcomes. Interhemishperic coherence between
homotopic neuronal populations may represent a biomarker of genuine motor recovery after
stroke.ix, 75 leaves : col. ill. ; 29 cm
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Ashworth-Beaumont, Jim. "The effect of anodal transcranial direct current stimulation on spatial motor skill learning in healthy and spinal cord injured humans." Thesis, Brunel University, 2012. http://bura.brunel.ac.uk/handle/2438/7376.
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Anodal transcranial direct current stimulation (tDCS) is an intervention which is thought to enhance motor learning in healthy and stroke-injured states, when applied adjunctively during skill learning. We set out to investigate whether anodal tDCS might enhance functional rehabilitation from incomplete tetraplegic SCI. To address current limitations in the measurement of task-dependent skill, a novel integrated skill training and measurement task, the Motor Skill Rehabilitation Task (MSRT) was designed and developed. Measures of performance from this task delivered the functional measure of spatial motor skill learning, Task Productivity Rate (TPR). TPR was analysed and validated as a univariate dependent outcome, which is of potential importance to the future development of clinical measures measuring goal-directed motor skills. The MSRT was included alongside conventional behavioural measures in a repeated-measures RCT pilot study, the first to investigate the effect of anodal tDCS on rehabilitation of motor skill from chronic spinal cord injury. Adjunctive application of anodal tDCS had a statistically significant benefit upon retention of skill in the incomplete spinal cord injured population, but only when the independent factor of sensory acuity was included in the analysis. Differences between the development of task-dependent skill and generic dexterity over time suggested that spatial skill development was subject to an interaction of short-term and lasting effects. A larger study in healthy persons further investigated these phenomena, also applying Transcranial Magnetic Stimulation (TMS)–evoked measurements to investigate intervention-dependent effects upon the excitability of projections between the primary motor cortex and muscles involved in the prehension task. The findings revealed that active tDCS did not enhance skill learning at 7 days beyond the training period, but did significantly alter the development of motor skill following a period of learning and subsequent skill consolidation which was associated with underlying perturbation of motor control strategy. Significant and divergent patterns of cortical plasticity were evoked in projections to muscles necessary for reaching and grasping. The main findings of this thesis do not support anodal tDCS as an effective adjunctive means of enhancing spatial motor skill in rehabilitation from incomplete tetraplegic SCI. If applied in patient populations, the clinical benefits of anodal tDCS may be contingent both on the nature of the sensorimotor deficit affecting upper limb function and the spatial demands of the behavioural task. The findings of this project serve to inform further research in relation to the effect of anodal tDCS on the brain and behavioural outcomes, the potential for efficacy in target patient groups and the sensitivity of outcome measures to spatial and temporal dimensions of practical motor skills.
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Hoseini, Najmeh. "The effect of motor point associative stimulation (MPAS) and transcranial direct current stimulation (tDCS) on manual dexterity and sensorimotor neurophysiology." Thesis, Indiana University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3712436.
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Manual dexterity, the ability to manipulate objects with the hands, and the related position sense, or proprioception, are often impaired after stroke. Associative stimulation of motor points (MPAS) in hand muscles is known to modify motor cortex excitability and improve manual dexterity (McDonnell and Ridding, 2006).
However, it is not known whether the effect of this peripheral stimulation can be increased by central stimulation of sensorimotor cortex, in terms of function, proprioception, or cortical neurophysiology. Here we compare the functional and neurophysiological consequences of MPAS with and without transcranial direct current (tDCS) in healthy adults. MPAS was applied to two right hand muscles important for manual dexterity: APB and FDI. tDCS, a non-invasive brain stimulation technique, was simultaneously applied over left sensorimotor cortex. Both techniques stimulate motor as well as somatosensory pathways. Neurophysiological measures of motor cortex, including SICI (short intra-cortical inhibition), ICF (intracortical facilitation), and input/output (I/O) curve, were assessed with transcranial magnetic stimulation (TMS). Manual dexterity and proprioceptive acuity were also measured. 14 subjects completed 3 sessions of MPAS in combination with sham, anodal (excitatory) and cathodal (inhibitory) tDCS. 13 subjects completed 2 sessions of sham MPAS with sham or anodal tDCS. In combination with MPAS, anodal tDCS significantly increased the plateau of manual dexterity, increased cortical response to TMS, and tended to improve proprioceptive acuity compared to sham tDCS. The neural basis for the observed functional improvements may thus include somatosensory as well as motor cortex. Neither MPAS nor tDCS alone had any measurable effect. These results suggest that adding tDCS as a central intervention to complement peripheral MPAS may be a promising avenue of treatment for patients with impaired manual dexterity.
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Scheffler, Grit. "The potential of transcranial direct current stimulation to facilitate motor learning in children and young people with hemiplegic cerebral palsy." Thesis, University of Aberdeen, 2013. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=201982.
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Transcranial direct current stimulation (tDCS) is a non-invasive stimulation technique that modulates brain function by increasing or decreasing cortical excitability (Nitsche & Paulus, 2001). In chronic stroke patients tDCS has been shown to improve function of the affected arm when combined with rehabilitative motor training (e.g. Lindenberg et al., 2010) and thus has the potential to accelerate motor learning. Its potential as a treatment for upper limb function in hemiplegic cerebral palsy (CP) had not been explored, which was the principle aim of this doctorate. After literature reviews on CP and tDCS (Chapter 1) feasibility work in healthy subjects was conducted to develop and validate the experimental procedures (Chapters 2 to 5). Chapter 2 examined whether tDCS improved motor performance of the non-preferred hand in healthy right-handed adults. The sophisticated kinematic outcome measures detected changes in performance due to learning, but no effect of tDCS was found. In Chapter 3, a novel motor learning task was developed and validated in healthy children and adolescents. This task was added to the study protocol and using a revised study design tDCS was found again to have no benefit on either motor performance or motor learning in healthy adults (Chapter 4). Tolerability, perception and acceptance of electrical stimulation were explored in Chapters 5 and 6, with the former showing that tDCS was well tolerated by healthy adults. Using a qualitative research methodology Chapter 6 established that teenagers with CP and their parents had concerns over the application of electricity on the scalp and how little is currently known of tDCS effects in CP. In Chapter 7, tDCS was applied to a teenager with hemiplegic CP with no clear beneficial effects. Finally, the contribution of this doctoral work with regard to the use of tDCS for the rehabilitation of motor function in CP is discussed in Chapter 8.
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Bachtiar, Velicia Elizabeth. "Transcranial stimulation of the human primary motor cortices." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:0a0f5502-e07c-4d8c-bc04-10c0a1f107f3.
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The primary aim of this thesis is to investigate the physiological effects of transcranial direct current stimulation (tDCS) as applied to the primary motor cortex (M1). This research was largely motivated by the need to understand the basic physiological changes of tDCS, in order to evaluate its use as a potential tool in recovery after stroke, as well as its more general applicability as a tool to modulate plasticity. The experiments in this thesis assess the ability of tDCS to modulate the primary motor cortex in healthy controls. The effects of tDCS on cortical GABA and motor resting state functional connectivity were measured with magnetic resonance spectroscopy (MRS) and resting functional MRI (fMRI). Anodal stimulation reduced GABA concentration and increased functional connectivity in the stimulated M1. Testing these changes within the same individuals demonstrated that the magnitude of changes do not correlate across subjects. Novel evidence on the timecourse of GABA change demonstrated that the reduction in GABA is most prominent in the 30-minute period after stimulation. To determine whether the tDCS-induced modulations in inhibition is restricted to the stimulated hemisphere or whether inhibitory changes could be observed in the nonstimulated M1, or in the interhemispheric connections between the M1s, transcranial magnetic stimulation (TMS) was used to measure intracortical inhibition in each M1 and interhemispheric inhibition and facilitation in the contralateral M1. There were no polarity-specifc effects on intracortical inhibition within either M1, and no changes in interhemispheric excitability from the stimulated to non-stimulated M1. Development of a two-voxel MRS method at ultra high field (7 Tesla) allowed for concurrent measurements of cortical neurotransmitters from both M1s with excellent spectral quality and GABA quantifcation. This method was used to demonstrate the timecourse of tDCS-induced changes in neurochemicals concurrently from both M1s. Anodal stimulation reduced GABA in both the anode-targeted and non-stimulated M1. Cathodal stimulation decreased GABA and glutamate in the non-stimulated M1, with no concurrent changes in the cathode-targeted M1. Bilateral stimulation reduced glutamate in both M1 with no change in GABA.
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Buzuluk, A. "Fully Integrated Smart BLDC Motor Driver." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/41131.
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There is tendency for using lot of electromechanical drives instead of mechanical to create more automatic and convenient systems. This means increase of number of DC motors in different devices such as cars, air
conditions, computers, household appliances, manufacture machines etc. All this motors have to be driven in different operation modes. Such parameters as rotation speed, current angle, torque, noise should be
controlled. Fully integrated DC Motor driver is the cheapest and the most smart solution.
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Lommen, Jonathan Lyon Jacob. "Effects of Transcranial Direct-Current Stimulation on Gait Initiation in People with Parkinson’s Disease." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39959.
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Background: Gait initiation is a major issue in Parkinson’s disease (PD). Moreover, the effect of current treatment on motor deficits vary alongside individual differences and disease severity. In some cases, postural instability has been documented as a major side-effect and refractory symptom to dopaminergic medication. Despite these shortcomings, research involving other forms of therapy including deep brain stimulation (DBS) and transcranial magnetic stimulation (TMS), has evidenced the improvement of postural deficits in PD. In this regard, there is a strong rational for the modulation of subcortical brain activity via the application of non-invasive transcranial direct current stimulation (tDCS) to interconnected cortical brain structures. Purpose: Therefore, we sought to determine the effect of tDCS applied to the supplementary motor area (SMA), on gait initiation preparation and performance in PD. Methods: A within subjects repeated measures quasi-experimental design was used to investigate the effects of a 10-minute sham-controlled tDCS intervention. Clinically diagnosed participants (n=12) with idiopathic PD were tested on medication during two sessions that bookended one week. Those who had previously undergone other forms of brain stimulation, had diabetes, severe freezing of gait, or any other neurological or functional limitations that could interfere with gait initiation were excluded from the study. Statistical Analyses/Results: Two-way repeated measures ANOVAs with Bonferroni corrections and a post-hoc analyses when appropriate, revealed a significant reduction in the magnitude of center of pressure (CoP) displacement and velocity in the mediolateral (ML) direction following tDCS. Conclusions: Findings from this study provide insights that may guide scientific research regarding the effects of tDCS on gait initiation among those with PD. Additionally, our work may highlight the importance of ML postural stability for individuals with comorbid and/or pharmacologically induced postural instabilities.
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Amadi, Ugwechi. "Transcranial stimulation to enhance cortical plasticity in the healthy and stroke-affected motor system." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:bb27ac6f-a79d-459a-b5a0-e9a209ac7132.
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This thesis investigated transcranial direct current stimulation (tDCS) as applied to the motor system, and its ability to modulate underlying cortical processes and resultant motor behaviours. Functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) were employed to assess the extent to which tDCS induces quantifiable changes in neural structure and function in controls and stroke patients. Modifications in the connectivity of intrinsic functional networks following tDCS application were examined using resting state fMRI. Polarity-specific changes were found: cathodal (inhibitory) tDCS increased the strength of the default mode network and increased functional coupling between major nodes within the motor network. No significant effects were found following anodal (excitatory) tDCS. Although anodal tDCS elicited only subtle changes in resting activity, it is known to produce robust modifications of behaviour. Single and paired-pulse TMS were used to investigate the neurophysiological underpinnings of these changes. Consistent with the theory of homeostatic plasticity, anodal tDCS applied prior to task performance increased GABAA-mediated cortical inhibition and worsened behaviour. The specificity of these changes suggests a central role for the mechanism of surround inhibition. A longitudinal clinical trial in chronic stroke patients was conducted to determine the utility of tDCS as an adjunct in motor rehabilitation. Serial MRI scans revealed that, when combined with motor training, anodal tDCS increased functional activity and grey matter in primarily ipsilesional motor areas. These brain changes were correlated with behavioural improvements in the stroke-affected upper limb. The laterality of connectivity at baseline, as measured by resting state activity and corticospinal tract integrity, was predictive of response to the rehabilitation program, particularly in those stroke patients who received tDCS. Asymmetry favouring the contralesional hemisphere predicted greater behavioural gains. Such results underscore the importance of re-normalisation of structure and functional activity toward the lesioned hemisphere in stroke rehabilitation.
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Wall, Mark John. "Modulation of the swimming motor pattern in Xenopus embryos of GABAâ†B receptors and by direct reduction of potassium currents." Thesis, University of Bristol, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358228.
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MELLO, Marina Almeida de. "Efeitos da estimulação transcraniana por corrente contínua cerebelar sobre o aprendizado motor de indivíduos saudáveis." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/18281.
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CNPQ
Vários estudos têm sugerido que o cerebelo tem um papel crucial no aprendizado motor. Pesquisas sobre o efeito da estimulação cerebelar na excitabilidade cortical vêm sendo desenvolvidas, porém, a influência da polaridade da estimulação, assim como a lateralidade dos efeitos não são bem esclarecidos. Outra lacuna é o efeito da estimulação sobre funções motoras não específicas, como o aprendizado motor medido através do tempo de reação serial (TRS), e tarefas motoras complexas, como o teste de escrita, podendo ter estes teste resultados divergentes devido a diferentes mecanismos responsáveis por sua execução. Portanto, a presente dissertação é composta de dois estudos. O primeiro estudo teve como objetivo investigar os efeitos da estimulação transcraniana por corrente contínua cerebelar (ETCCc) sobre a excitabilidade do córtex motor primário ipsilateral e o aprendizado motor realizado com o membro superior contralateral em indivíduos saudáveis. Nele foram analisados os efeitos polaridade-dependente da ETCCc sobre o aprendizado e sobrea excitabilidade cortical de 15 indivíduos saudáveis. Para isso, um estudo crossover, controlado, pseudo-randomizado e triplo cego foi realizado. Os resultados deste estudo são apresentados no artigo original intitulado “Effect of cerebellar transcranial direct current stimulation (ctDCS) on ipsilateral primary motor cortex excitability and on motor learning in the contralateral upper limb.” e sugerem que a ETCCc independente da polaridade não foi capaz de modular a excitabilidade do córtex motor primário ipsilateral à estimulação, mas atrapalhou o aprendizado motor implícito do membro superior contralateral.O segundo estudo teve como objetivo investigar os efeitos dependente da polaridade da modulação cerebelar induzida pela ETCCc sobre duas formas de aprendizado, um implícito e não específico, medido através do TRS, e um complexo, observado no teste de escrita de indivíduos saudáveis. Tratou-se de um estudo crossover, controlado, pseudo-randomizado e triplo cego, no qual 12 voluntários saudáveis foram submetidos a três sessões de ETCCc (anódica, catódica e sham) e avaliados através de parâmetros da escrita e do TRS. Os resultados deste estudo são apresentados no artigo original “Effect of cerebellar transcranial direct current stimulation (ctDCS) on procedural learning and handwriting” e apontam para uma piora no aprendizado motor medido pelo tempo de reação serial e melhora no teste de escrita após de estimulação transcraniana por corrente contínua cerebelar catódica, e uma piora no teste de escrita após estimulação anódica. Os resultados apresentados nesta dissertação confirmam a influência do cerebelo tanto no membro contralateral como no ipsilateral, sendo o último com o qual tem ligações diretas. Também foi possível confirmar que tarefas com diferentes complexidades podem apresentar desempenhos divergentes após ETCCc. Esses achados contribuem para compreensão das funções cerebelares e podem, futuramente, guiar o desenvolvimento de protocolos ideias para o uso da ETCCc como ferramenta de reabilitação de pacientes com desordens cerebelares.
Several studies have suggested that the cerebellum plays a crucial role on motor learning. Research about the effect of cerebellar stimulation on cortical excitability have been developed, however, the influence of the stimulation polarity, and the laterality of the effects are not fully understood. Another gap is the effect of stimulation on non-specific motor functions, such as the motor learning measured by serial reaction time (SRT), and complex motor tasks such as handwriting test. Those tests might have divergent results due to different mechanisms responsible for their implementation. Thus, the present thesis is composed of studies. The first one aimed to investigate the effects of transcranial stimulation current cerebellar continuous (ctDCS) on the cortical excitability of contralateral M1 and motor learning on contralateral limb in healthy subjects. For this, the effects of ctDCS on motor learning and cortical excitability were assessed in 15 health subjects in a crossover and sham controlled design. The results for this study are presented on the original research paper “Effect of cerebellar transcranial direct current stimulation (ctDCS) on ipsilateral primary motor cortex excitability and on motor learning in the contralateral upper limb“ and suggest that ctDCS, regardless polarity, was not able to modulate ipsilateral M1 cortical excitability while both anodal and cathodal ctDCS over the cerebellar cortex have disrupted motor learning with contralateral limb. The second study aimed to investigate the effects of cerebellar modulation induced by ctDCS on two forms of learning, the first implicit and nonspecific, measured by the serial reaction time task (SRTT), and the second a complex, assessed by handwriting test in healthy subjects. For this, it was adopted a crossover and sham controlled design, in which 12 healthy volunteers underwent three tDCS sessions (anodal, cathodal and sham stimulation) and assessed by SRTT and handwriting test. Results for this study are presented on the original research paper “Effect of cerebellar transcranial direct current stimulation (ctDCS) on procedural learning and handwriting” and show that both anodal and cathodal ctDCS impaired the procedural learning assessed by SRTT. For the handwrite teste, cathodal cerebellar tDCS enhanced motor learning while anodal stimulation impaired it. The results shown in this thesis confirm the cerebellar influence in both ipsi and contralateral limbs, the latter being the on it has direct connections. It was also possible to confirm that tasks with different complexities can have divergent performances after ctDCS. This findings contribute to an understanding of cerebellar functions and could, in the future, guide the development of optimal protocols for ctDCS in patients with cerebellar disorders.
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Gordon, Pedro Caldana. "Excitabilidade cortical motora como preditora de resposta na esquizofrenia." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/5/5169/tde-14022019-084004/.
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O desenvolvimento da estimulação magnética transcraniana (EMT) permitiu o estudo de potenciais evocados motores eliciados pela estimulação direta do córtex cerebral de forma não-invasiva. Foi observado que diferentes paradigmas de estimulação cortical por EMT apresentam diferentes padrões de resposta, que posteriormente foram associados ao funcionamento de circuitos corticais GABAérgicos e glutamatérgicos do córtex motor, compondo assim índices de excitabilidade cortical motora (ECM). Ademais, desvios da normalidade de tais índices foram encontrados em diversas condições clínicas, incluindo transtornos mentais como a esquizofrenia. O uso dessas medidas também auxiliou o desenvolvimento da estimulação transcraniana por corrente contínua (ETCC), técnica que se mostrou capaz de produzir efeitos neuromodulatórios no sistema nervoso central de forma segura e com mínimos efeitos adversos. Tal técnica vem apresentando possibilidades terapêuticas promissoras, como por exemplo, tendo sido observado sua eficácia no alívio de alucinações auditivas de indivíduos com esquizofrenia. O uso de ETCC para tratamento de sintomas negativos da esquizofrenia também pode vir a se mostrar uma abordagem eficaz, e a análise da ECM pode auxiliar no entendimento dos seus mecanismos de ação e atuar como possível preditor de resposta terapêutica. O objetivo do presente estudo é avaliar o perfil de ECM em um grupo de indivíduos com esquizofrenia, e as possíveis influências de um protocolo terapêutico utilizando ETCC sobre essas medidas. Com esse objetivo, foi selecionada uma coorte de sujeitos com esquizofrenia que participou em ensaio clínico randomizado e controlado com placebo (estimulação sham), tendo a ETCC como intervenção ativa alvo. A ECM foi mensurada na avaliação inicial dos sujeitos, assim como após a primeira sessão de ETCC, e quando da avaliação de desfecho primário. O protocolo terapêutico de ETCC envolveu a colocação de 2 eletrodos de área 5x7 cm, pólo anódico aplicado sobre região correspondente ao córtex pré-frontal dorsolateral esquerdo e pólo catódico aplicado sobre córtex de transição temporoparietal esquerdo; com intensidade de corrente de 2 mA, aplicada por 20 minutos. Cada sujeito foi submetido a 10 sessões no total. Encontramos que idade se correlacionou com diminuição da inibição intracortical, reproduzindo resultado previamente encontrado em indivíduos saudáveis. Acerca da modulação da ECM após sessão de ETCC, observamos que sujeitos submetidos à intervenção ativa apresentaram aumento da inibição intracortical no hemisfério estimulado, em oposição à ausência de mudança significativa da ECM nos sujeitos que receberam estimulação placebo. Os resultados sugerem que sessão de ETCC, utilizando os parâmetros aplicados neste estudo, levou ao aumento da inibição intracortical. Devido a evidências prévias de déficit de inibição intracortical em pessoas com esquizofrenia, é possível que o fenômeno observado represente mecanismo terapêutico da ETCC. É necessário verificar se tal efeito sobre a ECM acompanha medidas objetivas de resposta clinica. Caso isto se comprove, a ECM pode se tornar um valioso marcador de resposta terapêutica e evolução clinica em pacientes com esquizofreniaThe development of transcranial magnetic stimulation allowed the study of motor evoked potentials by applying direct stimuli to the brain cortex in a non-invasive fashion. Different stimulation protocols were observed to yield different response patterns, which were later associated with the functioning of cortical GABAergic and glutamatergic circuits, assembled as motor cortex excitability indices. Also, deviations from normality of such indices were observed in several clinical conditions, including mental disorders such as schizophrenia. The use of these measurements also helped the development of transcranial direct current stimulation (tDCS), a technique which was shown to promote neuromodulatory effects in central nervous system, with potential treatment applications. This technique has been used with success in the treatment of auditory hallucinations in patients with schizophrenia. The use of tDCS might also be effective in the treatment of negative symptoms of schizophrenia, and motor cortex excitability analysis might be used to clarify its physiological effects and act as a possible treatment response predictor. The aim of the present study is to evaluate the motor cortical excitability profile of individuals with schizophrenia, as well as possible influences of tDCS over these measurements. With this aim, we selected a cohort of subjects with schizophrenia who participated in a randomized placebo controlled clinical trial using transcranial direct current stimulation (and sham stimulation for placebo), and measuring motor cortical excitability during baseline evaluation, after the first stimulation session, and at the time of the primary outcome evaluation. The transcranial direct current stimulation protocol used in the present study involved the use of 2 electrodes of area 5x7 cm, anode placed over the region corresponding to the left dorsolateral prefrontal cortex, and cathode over the left cortical temporoparietal juntion. A current of 2 mA intensity was applied for 20 minutes. Each subject underwent a total of 10 sessions. We found that age was correlated to reduced intracortical inhibition, as has been previously found in healthy subjects. Regarding changes of motor cortical excitability following a transcranial direct current stimulation session, we observed that subjects that received the active stimulation displayed an increase in intracortical inhibition, as opposed to those who received sham stimulation, which did not present with any significant change. Results suggest that transcranial direct current stimulation session, using the parameters described in this study, led to an increase in intracortical inhibition. Given previous evidence of intracortical inhibition deficit in individuals with schizophrenia, it is possible that the observed phenomenon corresponds to a treatment mechanism of the electrical stimulation in this population. This need to be confirmed by comparing such changes in cortical excitability to objective measurements of clinical improvement. In case that is confirmed, measurement of motor cortical excitability may have a valuable application as a marker of treatment response and clinical outcome for patients with schizophrenia
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Gottwald, Michal. "Dynamický model stejnosměrného motoru s využitím metody konečných prvků." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219003.
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My diploma thesis deals with a specific dynamic model of DC motor with the parameters obtained from the calculation and from the program using the finite element method. It shows how much accurate results can be achieved in the model, if you use only the values which can be measured, recorded and calculated on the engine. This thesis contens three parts. First part describes the structure and function of DC motor and the basic principle and the use of FEM. Next is calculation analytical and numerical parameters. The search parameters include torque, resistance and inductance of armature winding, resistance and inductance of excitation windings. The last part is dedicated to creating a dynamic model. Results from the dynamic model and measured values are compared in the conclusion of my thesis.
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Macías, Cubeiro Rosa. "Development and Implementation of a Search and Locate Actuator System." Thesis, KTH, Elektrisk energiomvandling, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-109706.
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Over the last years, electrical roads have emerged as a cost effective and environmentally friendly solution towards a transportation system with less dependency on fossil fuels. This thesis presents the design of a search and locate system for road-bound conductive electrical roads with position control in two axes. The system is intended to find and follow the position of an electrified rail. The actuator system constitutes a firm groundwork for further research and development in this field. A laboratory test set up has been designed and both hardware and software parts have been constructed. The control of the system uses the CompactRIOTM technology from National Instruments. Results from the practical evaluation suggest that the non-linear characteristic of the system and the lack of direct position feedback from the motor rotation are the main causes of a non-accurate position control. Future development steps should focus on improving the mechanical design and include encoder feedback for the control loop as well as absolute automatic control with the incorporation of rail sensors.
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Akremi, Haifa. "Évaluation de l’efficacité de l’application de la stimulation à courant direct sur l’apprentissage moteur des enfants ayant un trouble de l’acquisition de la coordination." Mémoire, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/11092.
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Introduction : Les enfants ayant un trouble de l‘acquisition de la coordination (TAC) éprouvent de la difficulté à apprendre des gestes moteurs, particulièrement ceux demandant de la coordination motrice. Des nombreuses études en neuroimagerie ont mis en évidence une diminution de l‘activité neuronale au niveau du cervelet, ce qui pourrait être à l‘origine des difficultés d‘apprentissage moteur chez les enfants ayant un TAC. Augmenter l‘activité neuronale au niveau du cervelet afin d‘améliorer l‘apprentissage et la coordination motrice pourrait être une avenue prometteuse. La stimulation à courant direct (SCD) anodale permet d‘augmenter l‘activité neuronale de la région stimulée. L‘application de la SCD anodale au niveau du cervelet a montré une amélioration de l‘apprentissage moteur chez des populations en santé ou ayant des troubles neurologiques. À notre connaissance, aucune étude n‘a évalué l‘efficacité de l‘application de la SCD sur l‘apprentissage moteur des enfants ayant un TAC. Objectif : Ce projet vise à évaluer l‘efficacité de la SCD anodale appliquée au niveau du cervelet sur l‘apprentissage moteur et la coordination motrice du membre supérieur des enfants ayant un TAC. Méthodologie : Une étude expérimentale à devis avant-après avec un groupe témoin équivalent a été réalisée. Dix-neuf enfants âgés entre 10 et 17 ans ont été randomisés dans un des deux groupes (stimulation active ou stimulation placebo). Durant trois sessions, les participants ont reçu un courant anodal (de 2mA ou placebo) au niveau du cervelet. La stimulation a été effectuée durant 20 minutes pendant que les enfants réalisaient simultanément une tâche de pianotage sur le clavier d‘un ordinateur. Cette tâche, appelée « Serial Reaction Time Task (SRTT) », permet de mesurer la vitesse de réponse et le taux d‘erreur, lesquels ont été utilisés pour évaluer l‘apprentissage moteur. La coordination motrice du membre supérieur a été évaluée par le test doigt-nez (TDN) avant et après chaque application de la SCD. Résultats : L‘application de la SCD n‘a pas eu effet statistiquement significatif sur l‘apprentissage moteur, bien qu‘une tendance ait été observé quant à la réduction du taux d‘erreur pour le groupe actif par rapport au groupe placebo (p=0.072). Aucune différence statistiquement significative n‘a été observée pour la vitesse de réponse et la coordination motrice entre les 2 groupes. Conclusion : La SCD anodale pourrait potentiellement améliorer l‘apprentissage moteur chez les enfants ayant un TAC, particulièrement en regard de la diminution du taux d‘erreur. Cependant, plus de recherches sont nécessaires afin d‘explorer si la SCD pourrait être un outil ayant un potentiel thérapeutique intéressant pour bonifier l‘efficacité des interventions visant l‘apprentissage moteur des enfants ayant un TAC.Abstract : Introduction: Children with developmental coordination disorder (DCD) have difficulties learning motor tasks, especially for the ones requiring motor coordination. Numerous neuroimaging studies demonstrated a decrease in neuronal activity in the cerebellum, what might be responsible for motor learning difficulties in children with DCD. Increasing neuronal activity in the cerebellum might be an interesting avenue to improve learning and motor coordination. Anodal transcranial direct current stimulation (a-tDCS) has been shown to increase neuronal activity of the stimulated region, and to improve motor learning in healthy adults or patients with neurological disorders. To our knowledge, no study has assessed the tDCS effectiveness on motor learning for children with DCD. Objective: The present study evaluates the effect of cerebellar a-tDCS application on the motor learning and upper limb coordination of children with DCD. Methods: A pre-post experimental study with an equivalent control group was performed. Nineteen children aged 10-17 years were randomized in one of the two groups (active or placebo stimulation). During three sessions, participants received an anodal stimulation (2mA or placebo) on the cerebellum. The stimulation was carried out for 20 minutes while children simultaneously performed the Serial Reaction Time Task (SRTT), used to document motor learning through response speed and error rate. The motor coordination of the upper limb was evaluated by the finger-nose test (FNT) before and after each tDCS session. Results: The cerebellar a-tDCS could not significantly improve motor learning but a clinical reduction on error rate for the active group versus placebo group (p=0.072). The tDCS application did not show significantly improvement on speed and motor coordination between two groups. Conclusion: The a-tDCS could potentially improve motor learning by decreasing the error rate of children with DCD. However, more researches are needed to explore if the tDCS could be an interesting therapeutic tool to improve the effectiveness of motor learning interventions for children with DCD.
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Vala, Tomáš. "Analýza a inovace elektrických motorků pro automobily." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219751.
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Electric drives used in automotive industry are often based on standard DC motor as it is widely recognised as mature and reliable technology. The most common applications of DC motors in automotive industry are starters and wind screen wiper motors. Aim of this thesis is to provide design overview of typical automotive DC motor therefore main parts and features of the machine will be described in detail. Main disadvantage of DC motor is „sliding contact“ between commutator and carbon brushes which introduces source of electromagnetic disturbance and requires regular maintenance. Within this project different aspects of DC motor design and innovation are expected to be tackled including examples of loss calculation.
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Soares, Foerster Aguida [Verfasser], Michael [Akademischer Betreuer] Nitsche, André [Gutachter] Niklas, and Siegmar [Gutachter] Blumentritt. "Optimization of transcranial direct current stimulation (tDCS) to modulate lower limb motor network in healthy humans / Aguida Soares Foerster ; Gutachter: André Niklas, Siegmar Blumentritt ; Betreuer: Michael Nitsche." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://d-nb.info/1166670805/34.
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MELO, Lorena Figueiredo de. "Efeitos das estimulações cerebelares não invasivas no aprendizado motor e equilíbrio de indivíduos saudáveis." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/18609.
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A presente dissertação apresenta dois estudos com o intuito de avançar no conhecimento das repercussões das estimulações cerebelares no aprendizado motor e equilíbrio de indivíduos saudáveis. O estudo 1 se propôs a investigar os efeitos polaridade-dependentes da estimulação transcraniana por corrente contínua cerebelar (ETCCc) no equilíbrio de indivíduos saudáveis. O estudo 2, verificou os efeitos da ETCCc e da estimulação magnética transcraniana repetitiva cerebelar (EMTr-c) no aprendizado motor de saudáveis. No primeiro estudo, 15 voluntárias saudáveis e destras foram submetidas a três sessões de ETCCc (anódica, catódica e sham) no hemisfério cerebelar direito em ordem contrabalanceada. Em cada sessão, o equilíbrio estático e dinâmico foi avaliado pela ferramenta Biodex Balance System antes e após cada estimulação, através dos testes Athlete Single Leg Stability e Limits of Stability. Os resultados apontaram para uma piora no equilíbrio estático após a ETCCc catódica, avaliado pelo Athlete Single Leg Stability do membro inferior esquerdo em comparação com os valores basais (p=0,01) e com a ETCCc sham (p=0,04). Dessa forma, é possível afirmar que a ETCCc catódica foi capaz de interferir no equilíbrio estático de indivíduos saudáveis. O segundo estudo foi realizado com 18 voluntários destros, submetidos a seis sessões em ordem contrabalanceada. As sessões consistiram na aplicação dos seguintes protocolos sobre o hemisfério cerebelar esquerdo: (i) ETCCc anódica; (ii) ETCCc catódica; (iii) ETCCc sham; (iv) EMTr-c 10 Hz; (v) EMTr-c 1 Hz e (vi) EMTr-c sham. O aprendizado motor online (durante a estimulação) e offline (após a estimulação) foi avaliado através do teste de reação serial (aquisição e evocação) e teste de escrita (duração total e precisão do movimento), respectivamente. Foi observado que para o aprendizado motor online, as EMTr-c 1 Hz (p=0,018) e 10 Hz (p=0,010) e ETCCc catódica (p=0,001) foram capazes de alterar a aquisição, enquanto que todas as estimulações (p<0,05), com exceção da anódica (p=0,126), foram capazes de interferir na evocação da sequência aprendida. Em relação ao aprendizado motor offline, houve redução da duração total da escrita para todas as condições de estimulação (p<0,05). Para a precisão do movimento, houve melhora apenas para as condições: ETCCc anódica (p=0,003), EMTr-c 1 Hz (p=0,006) e 10 Hz (p=0,014). Portanto, a EMTr-c parece melhorar o aprendizado motor independente da frequência de estimulação e do momento da execução da tarefa (online ou offline). Por outro lado, o efeito da ETCCc mostra-se polaridade-dependente, visto que apenas a ETCCc anódica melhorou o aprendizado offline e a catódica apresentou melhores resultados para o aprendizado online.
This dissertation comprises two studies in order to understand the effects of cerebellar stimulations on motor learning and postural balance of healthy individuals. The first experiment (study 1) aimed to investigate the polarity-dependent effects of cerebellar transcranial direct current stimulation (ctDCS) on postural balance in healthy volunteers. The second experiment (study 2) aimed to evaluate ctDCS and cerebellar repetitive transcranial magnetic stimulation (c-rTMS) effects on motor learning in healthy individuals. In the first study, 15 righ-handed healthy volunteers were submitted to three ctDCS sessions (anodal, cathodal and sham) in a counterbalanced order. In each session, static and dynamic balance were evaluated by the Biodex Balance System before and after each stimulation through the Athlete Single Leg Stability and Limits of Stability tests. It was found a worsening static balance after cathodal ctDCS, assessed by Left Athlete Single Leg Stability test when compared to baseline (p=0.01) and sham stimulation (p=0.04). Thus, it is reasonable to assume that cathodal ctDCS was able to interfere on static balance in healthy individuals. The second experiment (study 2) was performed with 18 righthanded volunteers submitted to six session in a counterbalanced order. In each session, the left cerebellar hemisphere was modulated by the following protocols: (i) Anodal ctDCS; (ii) Cathodal ctDCS; (iii) Sham ctDCS; (iv) 10 Hz c-rTMS; (v) 1 Hz crTMS and (vi) Sham c-rTMS. Motor learning was evaluated during (online) or after (offline) stimulation protocols by the serial reaction test (acquisition and evoking phases) and handwriting test (duration and movement precision), respectively. It was observed that for online motor learning, 1 Hz c-rTMS (p=0.018) and 10 Hz (p=0.010) and also cathodal ctDCS (p=0.001), were able to interfere on acquisition phase. All stimulations (p<0.05) except for anodal ctDCS (p=0.126) were able to interfere when the learned sequence was evoked. Regarding offline motor learning, results revealed a reduction of duration for all stimulation conditions. However, for movement precision it was found an improvement for anodal ctDCS (p=0.003), 1 Hz c-rTMS (p=0.006) and 10 Hz c-rTMS (p=0.014). Therefore, c-rTMS seems to improve motor learning independently of stimulation frequency and time (online or offline). On the other hand, ctDCS effects were polarity-dependent since anodal ctDCS was capable to modulate offline learning, while cathodal ctDCS showed better results for online motor learning performance.
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Florian, Radim. "Model nelineární soustavy." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228233.
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The Thesis provides the project and realization of non-linear system, consisting of direct electric motor and dynamo that are linked together with flexible connector. Firstly, there are decscribed the principles of turns control in direct motor. Secondly, the thesis shows the construction of operating panel with microcontroller PIC16F877. Finally, the last part brings the evaluation of mesurements and suggests various improvements of the operational panel.
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Mosayebi, Samani Mohsen [Verfasser], Michael [Akademischer Betreuer] Nitsche, Adam Akademischer Betreuer] Woods, and Jens [Gutachter] [Haueisen. "Optimizing the neuroplastic effects of cathodal transcranial direct current stimulation over the primary motor cortex and transferability to prefrontal cortex / Mohsen Mosayebi Samani ; Gutachter: Jens Haueisen ; Michael Nitsche, Adam Woods." Ilmenau : TU Ilmenau, 2021. http://d-nb.info/1226092284/34.
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Baratieri, Cassio Luciano. "Controle de velocidade sensorless de motores brushless DC submetidos a variações periódicas de carga." Universidade Federal de Santa Maria, 2011. http://repositorio.ufsm.br/handle/1/8493.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThis master thesis presents a sensorless speed control drive of Brushless DC motors used in reciprocating compressors. These compressors cause periodic load torque variations on the motor, consequently mechanical vibrations and acoustic noise are presented as well. As a result, a discrete speed controller based on the internal model principle is proposed. This controller aims to track the speed reference and to reduce the periodic torque disturbances caused by the compressor. The proposed controller consists of a rotor position and speed estimator, and a discrete speed controller with variable sampling frequency that depend on the rotor speed. The discrete estimator is based on the zero crossing point detection of the back-electromotive force. This method is optimized by using a Least Squares algorithm. The speed controller consists of two control actions, repetitive and proportional-derivative actions. In order to complement the drive system operation, a new procedure to start a BLDCM with current control is proposed. This technique ensures the maximization of the electromagnetic torque during startup and to avoid demagnetization of the permanent magnet by the stator current. Finally, simulation and experimental results are presented to demonstrate the performance of the techniques adopted, as well as the main advantages, disadvantages and operational limitations of the experimental implementation. In addition, the performance of the load torque rejection is evaluated by comparing the harmonic spectrum of the torques produced by the proposed speed controller and a PI controller.
Esta dissertação apresenta um sistema de acionamento e controle de velocidade sensorless para motores Brushless DC utilizados em compressores alternativos. Estes compressores provocam variações periódicas de carga sobre o motor causando vibrações mecânicas e ruído acústico. Em vista disso, um controlador discreto de velocidade baseado no princípio do modelo interno é proposto. Este controlador visa o rastreamento assintótico de uma velocidade de referência e a redução dos distúrbios cíclicos de conjugado provocados pelo compressor. Para isso, o sistema proposto é constituído por um estimador discreto da posição e da velocidade do rotor, e um controlador discreto de velocidade com frequência de amostragem variável em função da velocidade de rotação. O estimador discreto baseia-se na deteção do cruzamento da força contra-eletromotriz por zero, a qual é otimizada por meio de um algoritmo de Mínimos Quadrados. O controlador de velocidade é composto por duas ações de controle, uma ação repetitiva e uma proporcionalderivativa. De forma a complementar a operação do sistema de acionamento, um novo procedimento de partida com controle de corrente é proposto para o BLDCM. Este procedimento possibilita a maximização do conjugado eletromagnético do motor durante a partida e ainda evita a desmagnetização dos ímãs pela incidência de altas correntes estatóricas. Por fim, resultados de simulação e experimentais são apresentados para demonstrar o desempenho das técnicas adotadas, assim como as principais vantagens, desvantagens e limitações operacionais da implementação experimental. Além disso, a performance da rejeição parcial do conjugado de carga é avaliada com a comparação do espectro harmônico dos conjugados produzidos pelo controlador de velocidade proposto e por um controlador proporcional-integral.
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Kotačka, Petr. "Zařízení na výrobu vlákna z termoplastu PET pro použití k 3D tisku metodou FDM." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254355.
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This thesis deals with design of equipment for the production of PET termoplastic fibre to be used in 3D printing by means of FDM method. Concise survey of plastics processing methods is presented herein, furthermore, structural design of equipment with necessary engineering calculations is included as well. Drawing documents with the total economic evaluation is a part of this thesis too.
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Lapenta, Olivia Morgan. "Efeito da neuromodulação em ritmo mu durante observação e mentalização de movimentos biológicos e não-biológicos." Universidade Presbiteriana Mackenzie, 2012. http://tede.mackenzie.br/jspui/handle/tede/1584.
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The Mental Simulation theory suggests activation of the motor network during imagery and execution of movements, similarly to the activation during observation and execution of actions, which is mediated by the Mirror Neuron System. This activation can be measured using eletroencefalography register of Mu rhythm suppression. It is propose that motor network activation and therefore increase of cortical excitability at primary motor cortex and Mu dessynchronization are due to premotor Miror-Neuron System inputs. Transcranial direct current stimulation is a neuromodulation technique that induce facilitation and inhibition of neural firing leading to enhance or decrease in cortical excitability, respectively. Thus, we propose to evaluate the polarity dependent effects of this technique in the Mu rhythm during biological and non-biological movements observation and imagery tasks. Therefore we applied anodal, cathodal and sham stimulation in 21 male subjects (mean age 23.8+3,06), over left primary motor cortex (2mA for 20min) and immediately after we registered the electroencephalography considering the electrodes C3, C4 and surrounding C3 and C4 and Cz. Analyses of C3 and C4 showed significant effects according to Movement (p=0.005), and also for the interactions between type of stimulation and hemisphere (p=0.04) and type of stimulation, movement and hemisphere (p=0.02). Surrounding electrodes analyses revealed significant effect for the interaction between stimulation type, task condition and movement type (p=0.03). Thus, the main findings of this study were i. Mu suppression for biological movement (in both imagery and observation) of the hand region in the contralateral hemisphere after sham stimulation, ii. reverse effect for the surrounding electrodes during imagery condition and iii. polarity-dependent neuromodulation of the Mu rhythm. The results are discussed considering focal ERD/ surrounding ERS according to the type of task. We concluded that there are contralateral focal Mu dessynchronization during observation and imagery of biological movements together with syncronizarion of the motor areas not involved in the task only for the imagery condition and that transcranial direct current stimulation has a significant effect under the entire electrode and according to the applied polarity. The use of transcranial direct current stimulation followed by observation and imagery tasks might be an interesting intervention strategy for disturbances involving motor ability impairment as well as deficits related to imitation and comprehension of other s actions.
A teoria de simulação mental sugere ativação da rede neural motora durante mentalização e execução de movimentos, de maneira análoga à ativação em observação e execução de ações, o que é mediado pelo Sistema de Neurônios-Espelho. Esta ativação pode ser mensurada por supressão do ritmo Mu registrado por eletroencefalografia. É proposto que a ativação de áreas motoras e, portanto, o aumento de excitabilidade cortical em cortex motor primário e a dessincronização do ritmo Mu ocorram em consequência de insumo proveniente do Sistema Neurônios-Espelho pré-motor. A estimulação transcraniana por corrente contínua consiste numa técnica de neuromodulação por facilitação e inibição de disparo neuronal levando a aumento e redução de excitabilidade cortical, respectivamente. Assim, foi proposto avaliar os efeitos polaridade dependentes desta técnica sobre ritmo Mu durante tarefas de observação e mentalização de movimentos biológicos e não biológicos. Para tal, aplicamos estimulação anódica, catódica e placebo em 21 homens destros (idade média de 23.8+3,06), sobre córtex motor primário esquerdo (2mA por 20min) e, em seguida foi feito o registro eletroencefalográfico considerando os eletrodos C3, C4 e entorno de C3 e C4 e Cz. A análise de C3 e C4 apresentou efeitos significativos quanto ao tipo de Movimento (p=0.005) e ainda quanto as interações entre tipo de estimulação e hemisfério (p=0.04) e tipo de estimulação, de movimento e hemisfério (p=0.02). A análise dos eletrodos do entorno revelou efeito significativo para a interação entre tipo de estimulação, condição da tarefa e tipo de movimento (p=0.03). Assim, os principais achados do estudo foram i. supressão de Mu para movimento biológico (em mentalização e observação) da região da mão em hemisfério contralateral após estimulação placebo, ii. efeitos inversos para eletrodos de entorno em condição de mentalização e iii. neuromodulação polaridade dependente de ritmo Mu. Os resultados de oscilação de Mu são discutidos considerando ERD focal/ ERS entorno de acordo com o tipo de tarefa. Concluímos que há dessincronização contralateral focal de Mu durante observação e mentalização de movimentos biológicos, acompanhada por sincronização de áreas motoras não envolvidas na tarefa apenas na condição de mentalização e que a estimulação transcraniana por corrente contínua tem efeito sob toda a superfície do eletrodo e difere de acordo com a polaridade aplicada. O uso da estimulação transcraniana por corrente contínua combinada com tarefas de observação e mentalização pode conferir uma estratégia interessante de intervenção em distúrbios envolvendo comprometimento das habilidades motoras bem como comprometimento de habilidades de imitação e compreensão das ações do outro.
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Špaček, Ladislav. "Analýza a inovace elektrických motorků pro automobily." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219009.
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Direct current motors and stepping motors are very often used for electric drives in cars. The most frequent representatives of direct current motors are electric starter and wind- screen wiper motor. Stepping motors are very often used for electric regulating of outsides driving mirrors and seats. This study is focused on innovation and DC permanent magnet motor. The disadvanage of direct current motors is so called „sliding contact“. A possible compensation of direct current motor are EC (electronically commutator) motors that do not need sliding contact for their work.
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Sláma, Miloslav. "Mechanismus vysouvání pastorku automobilového startéru." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221191.
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The thesis describes ways ejection pinions automotive starter and evaluation of the advantages and disadvantages of each solution. The first chapter deals with the principle of operation of DC motors and starters parameters. In the second part, the individual systems are theoretically discussed in terms of design and their advantages and disadvantages. The third part is focused on the most common system, which is analyzed in terms of mechanical and electrical reliability. The last point of the work is to design an experimental analysis Reach starter pinion.
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Lopes, Jamile Benite Palma. "Realidade virtual e estimulação transcraniana por corrente contínua anódica para melhora da função motora de membros superiores em crianças com síndrome de down: ensaio clínico controlado aleatorizado e duplo cego." Universidade Nove de Julho, 2017. http://bibliotecatede.uninove.br/handle/tede/1871.
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Objective: To perform a comparative analysis of the effects of manual reach training through virtual reality in the upper limb, with and without the association of transcranial stimulation by direct current of children with Down's Syndrome. Materials and methods: Study I: A systematic review was conducted with a search in four databases, according to: randomized controlled study; virtual reality, cerebral palsy; Down Syndrome published between 2010 and 2016. Study II: A systematic review was conducted with a search in four databases according to: randomized controlled study; cross-sectional study; evaluation; motion analysis; Dowm syndrome; Member published between 2010 and 2016. Study III: Detailed description of the protocol of a virtual reality intervention study associated with transcriana stimulation by direct current. Study IV: Comparative study between children with Down Syndrome and with typical Development, making a relation between the parameters of motor function of the upper limbs to the assessments constituted by single evaluation of three-dimensional analysis of the movement. Study V: ETCC anodic was performed with an intensity of 1 mA in bilateral M1 in a sample of 24 children with Down Syndrome, allocated in two groups (active and sham). The pacing protocol was performed with three training sessions per week, and the evaluations took place in three moments: pre, post-protocol and 1-month follow-up, consisting of three-dimensional analysis of manual upper limb movement, quality of manual skills and brain activity in the C3 and Cz regions of the cortex. Materials and methods: Study I: A systematic review was conducted with a search in four databases, according to: randomized controlled study; virtual reality, cerebral palsy; Down Syndrome published between 2010 and 2016. Study II: A systematic review was conducted with a search in four databases according to: randomized controlled study; cross-sectional study; evaluation; motion analysis; Dowm syndrome; Member published between 2010 and 2016. Study III: Detailed description of the protocol of a virtual reality intervention study associated with transcriana stimulation by direct current. Study IV: Comparative study among children with Down Syndrome and with typical Development, making a relation between the parameters of motor function of the upper limbs to the assessments constituted by single evaluation of three-dimensional analysis of the movement. Study V: ETCC was performed with an intensity of 1 mA in bilateral M1 in a sample of 24 children with Down Syndrome, allocated in two groups (active and sham). The pacing protocol was performed with three training sessions per week, and the evaluations took place in three moments: pre, post-protocol and 1-month follow-up, consisting of three-dimensional analysis of manual upper limb movement, quality of manual skills and brain activity in the C3 and Cz regions of the cortex.
Objetivo: Realizar uma análise comparativa dos efeitos do treino de alcance manual por meio da realidade virtual em membro superior, com e sem a associação da estimulação transcraniana por corrente contínua de crianças com Síndrome de Down. Materiais e método: Estudo I: Foi realizada uma revisão sistemática com uma busca em quatro bases de dados, de acordo com: estudo controlado randomizado; realidade virtual, paralisia cerebral; Síndrome de Down publicados entre 2010 e 2016. Estudo II: Foi realizada uma revisão sistemática com uma busca em quatro bases de dados de acordo com: estudo controlado randomizado; estudo transversal; avaliação; análise de movimento; Síndrome de Dowm; membro superior publicados entre 2010 e 2016. Estudo III: Descrição detalhada do protocolo de um estudo de intervenção de realidade virtual associada a estimulação transcriana por corrente contínua. Estudo IV: Estudo comparativo entre crianças com Síndrome de Down e com desenvolvimento típico, fazendo uma relação entre os parâmentros de função motora dos membros superiores às avaliações constituídas por única avaliação de análise tridimensional do movimento. Estudo V: ETCC anódica realizada com uma intensidade de 1 mA em M1 bilateral numa amostra de 24 crianças com Síndrome de Down, alocadas em dois grupos (ativo e sham) - RESULTADOS PRELIMARES. O protocolo de estimulação foi realizado com três sessões de treino por semana, sendo que as avaliações ocorreram em três momentos: pré, pós-protocolo e follow-up de 1 mês, sendo constituída por análise tridimensional do movimento de alcance manual dos membros superiores, qualidade das habilidades manuais e atividade cerebral nas regiões C3 e Cz do córtex. Resultados: Estudo I: cinco ensaios clínicos foram selecionados com uma qualidade metodológica de 4 pontos ou mais na escala PEDro, sendo aceito para publicação no periódico Journal of bodywork and Movement Therapies. Estudo II: cinco ensaios clínicos foram selecionados com uma qualidade metodológica avaliados pelo instrumento de Avaliação Crítica Crowe, sendo submetido ao Journal Infant Behavior. Estudo III: artigo de protocolo de estudo com metodologia de intervenção com estimulação transcraniana por corrente continua associada a treino motor de realidade virtual, publicado no periódico BMJOPEN. Estudo VI: Os resultados da análise da cinemática do movimento de alcance manual entre crianças com desenvolvimento típico e Sindrome de Down apresentaram diferenças no aspecto da velocidade, tempo e acurácia do movimento. Estudo V: Os resultados deste estudo demonstraram que o grupo de crianças com SD que recebeu o treinamento com o protocolo de 10 sessões de 20 minutos de ETCC anódica sobre o córtex motor primário (C3 e C4) com montagem extracefalica bilateral apresentou respostas positivas a esta intervenção nos aspectos funcionais e do movimento dos MMSS nas avaliações realizadas logo após o término do protocolo, bem como ao follow-up de um mês pós intervenção em comparação com o grupo que recebeu ETCC Sham durante o mesmo tipo de treino motor. Conclusão: A combinação de treinamento funcional do alcance manual e ETCC anódica sobre o córtex motor primário bilateral em crianças com SD demonstrou resultados encorajadores, tanto a curto quanto a longo prazo no que diz respeito à melhora do movimento do MS, como não houve resultado significativo quando analisados dados prelimares de parâmetros da cinemática do movimento e aumento da melhora da qualidade das habilidades e de MMSS.
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Agboada, Desmond [Verfasser], Michael [Gutachter] Nitsche, Carmelo M. [Gutachter] Vicario, and Klaus [Gutachter] Funke. "A systematic evaluation of stimulation-specific parameters of anodal transcranial direct current stimulation for inducing LTP-like plasticity in the primary motor cortex / Desmond Agboada ; Gutachter: Michael Nitsche, Carmelo M. Vicario, Klaus Funke ; International Graduate School of Neuroscience." Bochum : Ruhr-Universität Bochum, 2021. http://d-nb.info/1226429122/34.
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Marques, Filho Paulo Ricardo. "Impacto da estimulação transcraniana por corrente contínua (ETCC) na resposta comportamental e neuroquímica de ratos submetidos a um modelo de dor neuropática." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/110202.
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A Associação Internacional para Estudos da Dor (IASP) define a dor neuropática como a dor que surge diretamente de uma lesão ou doença que afeta o sistema somatossensorial. Os sintomas mais característicos são a hiperalgesia e a alodinia. Além disso, alterações comportamentais como transtornos de ansiedade são comorbidades comuns associadas à dor crônica com características neuropáticas. Os métodos de neuromodulação transcraniana como a ETCC tem se mostrado promissores no tratamento da dor e de alguns transtornos neuropsiquiátricos, uma vez que parecem promover alterações neuroplásticas em nível central. Sendo assim, neste estudo avaliamos o efeito da ETCC na atividade locomotora e exploratória, no comportamento do tipo ansioso e na plasticidade medular e cortical em ratos submetidos a um modelo de dor neuropática. Foram utilizados 144 ratos machos Wistar com 55-65 dias de idade, divididos em 6 grupos: Sham Cirurgia (Sc), Sham Cirurgia+Sham ETCC (SsSE), Sham Cirurgia+ETCC (ScE), Dor Neuropática (Dn), Dor Neuropática+Sham ETCC (DnSE) e Dor Neuropática+ETCC (DnE). O modelo de dor neuropática foi realizado a partir da compressão parcial do nervo isquiático e no 14º dia após a cirurgia iniciou-se o tratamento. A ETCC foi aplicada durante 8 dias com sessões de 20 minutos e foi utilizada uma corrente de 0,5 mA de intensidade. O aparato de Campo Aberto e o Labirinto de Cruz Elevado foram avaliados em dois momentos 24h (Fase I) e sete dias (Fase II) após o tratamento. Os níveis de BDNF foram quantificados em dois momentos 48h (Fase I) e sete dias (Fase II) após a última sessão de tratamento. Nossos resultados demonstram que a dor neuropática induz a uma menor atividade locomotora e exploratória associado a um aumento do comportamento do tipo ansioso em ratos. Por outro lado, o tratamento com ETCC provoca aumento na locomoção e na atividade exploratoria associados à diminuição do comportamento do tipo ansioso. A ETCC mostrou ser capaz de induzir mudanças neuroplásticas alterando níveis de BDNF periférico e central. Concluindo, a ETCC foi capaz de alterar parâmetros comportamentais e neuroplásticos. Podendo ser uma técnica promissora para o tratamento de comorbidades associadas à dor neuropática.The IASP defines neuropathic pain as pain that arises directly from an injury or disease affecting the somatosensory system. The most characteristic symptoms are hyperalgesia and allodynia. Furthermore, behavior changes such as anxiety disorders are common comorbidities associated with chronic pain with characteristics neuropathic. Methods for Neuromodulation transcranial as tDCS are promising in the treatment of pain and some neuropsychiatric disorders, since they seem to further neuroplastic changes in the central level. In this study we evaluate the effect of tDCS on locomotor and exploratory activities, anxiety-like behavior and medullary and cortical plasticity in rats submitted to a neuropathic pain model. A total of 144 male Wistar rats (55-65 days-old; weighing 200–250 g) were divided into 6 groups: Sham Surgery (Ss), Sham Surgery+Sham tDCS (SsS), Sham Surgery+tDCS (SsT), Neuropathic Pain (Np), Neuropathic Pain+Sham tDCS (NpS) and Neuropathic Pain+tDCS (NpT). The model of neuropathic pain was performed by partial sciatic nerve compression and on the 14th day after surgery began tDCS treatment. The tDCS was applied for 8 days with 20-minute sessions and a current intensity of 0.5 mA was used. Open Field and the Plus Maze tests were evaluated at two times 24 (Phase I) and seven days (Phase II) after end of treatment. BDNF levels were quantified in two at 48h (Phase I) and seven days (Phase II) after the last treatment session. Our results demonstrate that neuropathic pain induced a decreased in the locomotor activity and exploratory activity associated with an increase in anxiety-like behavior in rats. On the other hand, treatment with tDCS causes an increase in locomotion and exploratory activity associated with a reduction in anxiety-like behavior. The tDCS proved able to induce neuroplastic changes in BDNF levels by altering the peripheral and central. In conclusion, tDCS changes behavior and neuroplastic parameters; thus it can be a promising technique for the treatment of comorbid conditions associated with neuropathic pain.
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Guimarães, ádller de Oliveira. "Algoritmo genético aplicado no controle de posição do rotor de um motor de corrente contínua com rejeição a distúrbios por ação feedforward." Universidade Federal Rural do Semi-Árido, 2013. http://bdtd.ufersa.edu.br:80/tede/handle/tede/517.
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Previous issue date: 2013-12-27The versatility of direct current machines combined with the relative simplicity of their drive systems ensures its continued use in a wide variety of applications in industrial electrical systems, more specifically in applications that requiring a wide range of speed and position control of the rotor. In this work, a new method for tuning Proportional-Integral-Derivative (PID) controllers with disturbance rejection using Genetic Algorithm (GA) is proposed. The proportional, integral and derivative gains, designed to control the rotor position of DC motor are optimized using GA in group with Ziegler - Nichols technique, and the rejection of disturbances is obtained from the implementation of feedforward control in the algorithm. Preliminary results show that the proposed GA gave a satisfactory response, both in transitional regime as at steady state, and shows good performance in disturbance rejection. To validate this technique, the results obtained were compared with other methods in literature
A versatilidade das máquinas de corrente contínua, combinada com a relativa simplicidade dos seus respectivos sistemas de acionamento, assegura a sua contínua utilização numa ampla variedade de aplicações em sistemas elétricos industriais, mais especificamente, em aplicações que exigem uma vasta gama de controle da velocidade e posição do rotor. Neste trabalho, um novo método de sintonia de controladores Proporcional-Integral-Derivativo (PID) com rejeição a distúrbios usando Algoritmo Genético (AG) é proposto. Os ganhos proporcional, integral e derivativo, projetados para controlar a posição do rotor do motor CC, são otimizados utilizando AG em conjunto com a técnica de Ziegler-Nichols, e a rejeição a distúrbios é obtida a partir da implementação no algoritmo do controle por ação Feedforward. Resultados preliminares mostram que o AG proposto, apresentou desempenho satisfatório da resposta, tanto em regime transitório quanto no estado estacionário, além de apresentar boa performance na rejeição a distúrbios. Para validar a técnica utilizada, os resultados obtidos foram comparados com outros métodos publicados na literatura
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Rego, Jeferson Tafarel Pereira do. "Efeito da estimula??o transcraniana por corrente cont?nua an?dica sobre o controle do movimento em para-halterofilistas." Universidade Federal do Rio Grande do Norte, 2014. http://repositorio.ufrn.br:8080/jspui/handle/123456789/14628.
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Previous issue date: 2014-03-21Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
Introduction: The sport practiced by people with disabilities has been growing in recent years. Consequently, advances in assessment and training methods have emerged. However, the paralympic sport keeps in tow these advances, with few specific studies that consider disability as intervening factor. The transcranial direct current stimulation (tDCS) is a technique that has proven to be capable of modulating brain function. Studies show beneficial effects of tDCS on muscle strength, power and fatigue during exercise. Objective: Investigate de the effect of tDCS on movement control in para-powerlifters. Methods: Eight subjects underwent two sessions of motion capture, which previously applied the anodic tDCS or sham sessions in the cerebellum. Three movements were performed with increasing load between 90-95% of 1MR. The movements were recorded by an 10 infrared cameras system which reconstructed the 3D trajectory of markers placed on the bar. Results: There have been changes between the anodic and sham conditions over bar level (initial, final, maximum during the eccentric and concentric phase) and in the difference between the final and initial bar level. Moreover, there was difference in bar level (final and during the eccentric phase) comparing athletes amputees and les autres. Conclusion: The findings of this study suggest that tDCS applied prior to the exercise over the cerebellum in para-powerlifters acts differently according to disability
Introdu??o: O esporte praticado por pessoas com defici?ncia vem crescendo nos ?ltimos anos. Consequentemente, avan?os nos m?todos de avalia??o e treinamento t?m surgido. Por?m, o esporte paral?mpico segue a reboque destes avan?os, com poucos estudos espec?ficos que considerem a defici?ncia como fator interveniente. A estimula??o transcraniana por corrente cont?nua (ETCC) ? uma t?cnica que vem se mostrando capaz de modular a fun??o cerebral. Estudos mostram efeitos ben?ficos da ETCC sobre a for?a muscular, fadiga e pot?ncia durante exerc?cio. Objetivo: Investigar o efeito da ETCC sobre o controle do movimento em para-halterofilistas. Metodologia: Oito sujeitos foram submetidos a duas sess?es de captura de movimentos, sendo aplicado previamente as sess?es ETCC an?dica ou sham no cerebelo. Foram realizados tr?s movimentos com carga crescente entre 90-95% de 1RM. Os movimentos foram gravados por um sistema com 10 c?meras infravermelho e tiveram reconstru?da a trajet?ria 3D de marcadores colocados na barra. Resultados: Houveram mudan?as entre as condi??es an?dica e sham sobre os desn?veis inicial, final, m?ximos durante a fase exc?ntrica e conc?ntrica e sobre a diferen?a entre o desn?vel inicial e final. Al?m disto, houve diferen?a no desn?vel final e durante a fase exc?ntrica ao comparar os atletas amputados e les autres. Conclus?o: Os achados do presente estudo sugerem que a ETCC aplicada previamente ao exerc?cio sobre o cerebelo em para-halterofilistas atua de forma diferenciada de acordo com a defici?ncia
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ANDERSSON, JOHAN, and RICKARD HÖGLUND. "Electric Load Driven Longboard." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279809.
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This bachelor’s thesis aims to show an extensive overview of all the parts that build up an electric load driven longboard and see if a load controlled longboard can be seen as a safe, comfortable and convenient alternative to the more common remote controlled longboard. The thesis will also answer how weight can be measured on a longboard in the most effective way, what the most comfortable riding technique is and what a good motor-battery configuration to be able to travel at 30 km/h and 10 km would be. The longboard measures the weight distribution with load cells located between the deck and the trucks. An Arduino translates the input from the load cells to a certain speed and then sends it to an ODrive which controls a BLDC motor that is powered by two LiPo batteries. The results show that a load controlled longboard can very well be seen as a good alternative if right riding technique is used. The best technique is when the longboard accelerates when the rider tilts and keeps a constant speed when the rider stands straight. The best way to measure the weight is to fasten the trucks with hinges which lets the load cells register weight without anything interfering. Not all tests could be done because of Covid-19 but a measured top speed of 15 km/h with a high gear ratio is a promising result for the future when more suitable gear ratios will be tested to try to reach the goal of 30 km/h.Det här kandidatexamensarbetet strävar efter att visa en omfattande överblick på alla delar som bygger upp en elektrisk lastdriven longboard och se om en laststyrd longboard kan ses som ett säkert, komfortabelt och behändigt alternativ till den vanligare radiostyrda longboarden via handkontroll. Det här arbetet kommer också svara på hur vikt kan mätas på en longboard på ett så effektivt sätt som möjligt, vad som är den mest bekväma åkstilen och vad är en bra motor-batteri konfiguration för att kunna åka i 30 km/h och nå 10 km skulle vara. Longboarden mäter viktfördelningen med lastceller som är placerade mellan brädan och truckarna. En Arduino omvandlar indatan från lastcellerna till en specifik hastighet som den sedan skickar till en ODrive som kontrollerar en borstlös likströmsmotor som i sin tur är driven av två LiPo batterier. Resultaten visar att en laststyrd longboard kan mycket väl ses som ett bra alternativ om rätt åkstil används. Den bästa stilen är att longboarden accelererar när åkaren lutar sig och håller en konstant hastighet när åkaren står rakt. Det bästa sättet att mäta vikt är att montera truckarna på gångjärn som låter lastcellerna mäta vikt utan att något stör. Alla tester kunde inte utföras på grund av Covid-19 men en uppmätt topphastighet på 15 km/h med en hög utväxling är ett lovande resultat för framtiden när lämpligare utväxlingar kommer testas för att försöka nå målet på 30 km/h.
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Šíl, Petr. "Návrh a realizace malosériové výrobní linky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254460.
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This Master's Thesis is focused on the design and control of a small-series production line, for the production of segmetal arches and plastic reductions. It is about the conversion from a semi-automatic line to a fully automatic line. The production line consists of an extruder, a cutting unit, a exhaust unit, three pressing machines and a manipulator. Every single machine has a custom control for which was selected a baseplate with microcontroler ATmega 128 and designed powerful part of inputs and outputs. There is a simple communication between the machines. Appropriate elements were used for conversion of every individual part of the production line. The whole system is programmed with software called AVR Studio4.
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Abdellatif, Meriem. "Continuité de service des entraînements électriques pour une machine à induction alimentée par le stator et le rotor en présence de défauts capteurs." Thesis, Toulouse, INPT, 2010. http://www.theses.fr/2010INPT0107/document.
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Le développement de commandes en boucle fermée pour des entraînements électriques nécessite l'installation de capteurs pour avoir l'information de la rétroaction. Cependant, un éventuel défaut survenant sur l'un des capteurs installés (de courant, de vitesse/position,…) implique un disfonctionnement de la commande conduisant dans la plupart du temps à la mise hors service du système. Ces conséquences sont contraires aux exigences des industriels qui demandent des degrés de fiabilité du système de plus en plus élevés. Des statistiques montrent que le défaut capteur est fréquent. Il est donc impératif de trouver des solutions pour assurer la continuité de service des systèmes électriques dans le cas de présence de ce type de défaut. Tout d'abord, l'étude présentée dans ce manuscrit présente les technologies des différents capteurs installés et ce pour comprendre les raisons et le type de pannes qui pourraient survenir. Ensuite, le système sur lequel la validation des algorithmes développés est décrit. Il s'agit d'un entraînement électrique basé sur une machine à Double Alimentation (MADA) fonctionnant en mode moteur et connectée au réseau via deux convertisseurs. La commande associée est une Commande Directe de Couple (CDC). Elle est validée en mode sain aussi bien par simulation qu'expérimentalement. Après, les études réalisées prennent en considération les défauts capteurs de courants alternatifs et de vitesse/position. Les algorithmes développés, permettant une continuité de service, utilisent une redondance analytique et sont basés sur l'estimation et aussi sur la Détection et l'Isolation d'un éventuel Défaut (DID). Ils sont caractérisés par leur simplicité. Aussi, ils ne sont pas gourmands en termes de consommation en ressources matérielles et leur temps d'exécution est très court. Enfin, la validation expérimentale de ces algorithmes montre bien leur efficacité en cas de défaut, vu que le système s'avère insensible au défaut et continue à fonctionner sans interruption. La commande obtenue est alors tolérante aux défauts capteursThe development of closed loop controls for electrical drives requires the sensor installations in order to get feed back information. Nevertheless, any occurred sensor fault (current sensor,speed/position sensor,…) shows an operation system deterioration which leads in most cases to its shut down. This consequence is in contrast to industrial expectations especially concerning the system high accuracy that they are asking for. Statistic studies point out the sensor faults as frequent. So, it is necessary to find out solutions ensuring the system service continuity in case of any sensor fault. Firstly, the study presented in this work shows the used sensor technologies in order to understand both of the reason and the kind of occurred faults. Secondly, the studied system is presented which is an electrical drive based on a Doubly Fed Induction Machine (DFIM) operating in motor mode and connected to the grid by two inverters. The control developed is a Direct Torque Control (DTC). The control validation, in healthy operating mode, is realised throw simulation and experimentally. After, a study considering alternative current sensor and speed/position sensor faults are achieved. The developed algorithms are based on signal estimation, on a Fault Detection Isolation (FDI) and reconfiguration algorithms. In fact, they are simple to carry out, they don't need much hardware resources for implementation and their execution time is short. Finally, the experimental validation of the developed algorithms shows their efficiency. The system continues working even in presence of a sensor fault. Thus, the obtained control becomes a fault tolerant control thanks to these algorithms
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Cabibel, Vincent. "Mécanismes physiopathologiques de l’altération de la commande motrice dans la bronchopneumopathie chronique obstructive." Thesis, Montpellier, 2020. http://www.theses.fr/2020MONT4004.
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La bronchopneumopathie chronique obstructive (BPCO) est une pathologie respiratoire chronique présentant de nombreuses comorbidités. La faiblesse musculaire, caractérisée par une diminution de la force musculaire (de 30% en moyenne par rapport aux sujets sains) en dehors de tout état de fatigue, est une complication majeure de la pathologie impactant très largement la vie des patients. La production de force dépend de deux processus physiologiques : la capacité du système nerveux à activer le muscle et la capacité du muscle à réaliser une contraction. Ces deux processus sont défaillants dans la BPCO. Cependant, si les altérations du muscle du patient atteint de BPCO sont bien documentées, les mécanismes impliqués dans la production d’une commande motrice non-optimale sont quant à eux mal compris. Le but de ce travail de thèse était donc d’identifier les mécanismes responsables de l’altération de la commande motrice chez les patients atteints de BPCO. Nos travaux ont confirmé l’existence d’une commande motrice réduite, par rapport à des sujets sains. L’utilisation de neuromodulation chez les patients n’a pas permis d’augmenter l’excitabilité corticale et la commande motrice, donc d’évaluer s’il existait des réseaux neuronaux latents chez les BPCO. Nous avons démontré qu’il existait une altération de la connectivité entre les hémisphères cérébraux des patients par rapport à des sujets sains et que l’activation des aires motrices ipsilatérales des patients n’était pas altérée lors de la production de force. Enfin, nous avons montré que les traitements psychoactifs, prescrits pour traiter le syndrome anxio-dépressif, étaient fortement prévalents dans la BPCO. Nous avons montré qu’ils induisent une réduction de l’excitabilité et une augmentation de l’inhibition au niveau cortical, ainsi qu’une altération de la commande motrice. Cependant, l’absence de répercussions sur la force volontaire suggère la présence d’un mécanisme compensatoireChronic obstructive pulmonary disease (COPD) is a respiratory pathology associated with several repercussions. The muscle weakness, characterized by a reduction of the muscle strength (30% on average, compared to healthy individuals) without any fatigue, is a major repercussion of the disease. Strength production relies on two physiological processes: the nervous system ability to activate the muscles and the capacity of the muscles to perform a contraction. Both these processes are impaired in COPD. However, while the muscles alterations are well documented, the mechanisms involved in the production of a non-optimal motor command are not fully understood. The aim of this thesis was therefore to identify the mechanisms involved in the motor command alteration in COPD patients. Our work confirmed the existence of a reduced motor command in COPD, compared to healthy subjects. The application of neuromodulation in patients failed to increase cortical excitability and motor command, and consequently to determine whether latent motor networks exists in COPD. We then demonstrated that the connectivity was altered between the brain hemispheres in COPD and that the ipsilateral motor areas activation was preserved in patients during force generation. Finally, we observed that psychoactive medications, prescribed to manage anxiety and depression, we highly prevalent in COPD. The consumption of these medications was associated with reduced excitability and increased inhibition at the cortical level and with an altered motor command. However, the absence of repercussion on strength suggests the existence of a compensatory mechanism