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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Simulation Of Biped Locomotion Of Humanoid Robots In 3d Space

Akalin, Gokcan 01 October 2010 (has links) (PDF)
The main goal of this thesis is to simulate the response of a humanoid robot using a specified control algorithm which can achieve a sustainable biped locomotion with 4 basic locomotion phases. Basic parts for the body of the humanoid robot model are shaped according to the specified basic physical parameters and assumed kinematic model. The kinematic model, which does not change according to locomotion phases and consists of 27 segments including 14 virtual segments, provides a humanoid robot model with 26 degrees of freedom (DOF). Corresponding kinematic relations for the robot model are obtained by recursive formulations. Derivation of dynamic equations is carried out by the Newton-Euler formulation. A trajectory definition algorithm which defines positions, orientations, translational and angular velocities for the hip and its mass center, toe part of the foot and its toe point is created. A control strategy based on predictive optimum command acceleration calculations and computed torque control method is implemented. The simulation is executed in Simulink and the visualization of the simulation is established in a virtual environment by Virtual Reality Toolbox of MATLAB. The simulation results and the user defined reference input are displayed simultaneously in the virtual environment. In this study, a simulation environment for the biped locomotion of humanoid robots is created. By the help of this thesis, the user can test various control strategies by modifying the modular structure of the simulation and acquire necessary information for the preliminary design study of a humanoid robot construction.
42

Modelling, simulation and analysis of low-cost direct torque control of PMSM using hall-effect sensors

Ozturk, Salih Baris 25 April 2007 (has links)
This thesis focuses on the development of a novel Direct Torque Control (DTC) scheme for permanent magnet (PM) synchronous motors (surface and interior types) in the constant torque region with the help of cost-effective hall-effect sensors. This method requires no DC-link sensing, which is a mandatory matter in the conventional DTC drives, therefore it reduces the cost of a conventional DTC of a permanent magnet (PM) synchronous motor and also removes common problems including; resistance change effect, low speed and integration drift. Conventional DTC drives require at least one DC-link voltage sensor (or two on the motor terminals) and two current sensors because of the necessary estimation of position, speed, torque, and stator flux in the stationary reference frame. Unlike the conventional DTC drive, the proposed method uses the rotor reference frame because the rotor position is provided by the three hall-effect sensors and does not require expensive voltage sensors. Moreover, the proposed algorithm takes the acceleration and deceleration of the motor and torque disturbances into account to improve the speed and torque responses. The basic theory of operation for the proposed topology is presented. A mathematical model for the proposed DTC of the PMSM topology is developed. A simulation program written in MATLAB/SIMULINK® is used to verify the basic operation (performance) of the proposed topology. The mathematical model is capable of simulating the steady-state, as well as dynamic response even under heavy load conditions (e.g. transient load torque at ramp up). It is believed that the proposed system offers a reliable and low-cost solution for the emerging market of DTC for PMSM drives. Finally the proposed drive, considering the constant torque region operation, is applied to the agitation part of a laundry washing machine (operating in constant torque region) for speed performance comparison with the current low-cost agitation cycle speed control technique used by washing machine companies around the world.
43

Mechatronics of holonomic mobile base for compliant manipulation

Gupta, Somudro 08 February 2012 (has links)
In order to operate safely and naturally in human-centered environments, robots need to respond compliantly to force and contact interactions. While advanced robotic torsos and arms have been built that successfully achieve this, a somewhat neglected research area is the construction of compliant wheeled mobile bases. This thesis describes the mechatronics behind Trikey, a holonomic wheeled mobile base employing torque sensing at each of its three omni wheels so that it can detect and respond gracefully to force interactions. Trikey's mechanical design, kinematic and dynamic models, and control architecture are described, as well as simple experiments demonstrating compliant control. Trikey is designed to support a force-controlled humanoid upper body, and eventually, the two will be controlled together using whole-body control algorithms that utilize the external and internal dynamics of the entire system. / text
44

Μελέτη και κατασκευή ηλεκτρονικής διάταξης για υβριδικό όχημα : ανάκτηση ενέργειας

Ζερβάκος, Αθανάσιος 27 April 2009 (has links)
Τα τελευταία 35 χρόνια έχει προκύψει ένα ενεργειακό πρόβλημα το οποίο μας επιβάλει να αλλάξουμε την ενεργειακή μας αντίληψη. Το πετρέλαιο αλλά και άλλα ορυκτά καύσιμα έχουν πεπερασμένα αποθέματα και η χρήση τους επιβαρύνει το περιβάλλον. Επίσης γεωπολιτικά συμφέροντα δεν επιτρέπουν την ανεμπόδιστη διανομή του. Μέσα σε αυτό το κλίμα της ενεργειακής απεξάρτησης από τα ορυκτά καύσιμα αναπτύσσονται τα τελευταία χρόνια τα υβριδικά οχήματα. Τα ηλεκτρικά υβριδικά οχήματα είναι ένα μεταβατικό στάδιο από την πετρελαιοκίνηση στην εξ’ ολοκλήρου κίνηση μέσω ηλεκτρισμού από ενεργειακές κυψέλες. Αποτελούνται από έναν συμβατικό κινητήρα εσωτερικής καύσης και μια ηλεκτρική μηχανή, η οποία τροφοδοτείται από συσσωρευτές. Τα υβριδικά οχήματα χωρίζονται σε διάφορες κατηγορίες ανάλογα με τις τεχνολογίες υβριδοποίησης που διαθέτουν και την διάταξη του ηλεκτρομηχανολογικού τους συστήματος. Στόχος της παρούσας διπλωματικής εργασίας (η οποία είναι η συνέχεια δυο προηγούμενων) είναι η προσπάθεια κατασκευής ενός υβριδικού αυτοκινήτου. Για να γίνει αυτό εφικτό απαιτούνται, ένα όχημα το οποίο να μπορεί να δεχθεί εύκολα μηχανολογικές μετατροπές, ένας ηλεκτρικός κινητήρας και συσσωρευτές. Ο ηλεκτρικός κινητήρας ελέγχεται από έναν αντιστροφέα. Ο αντιστροφέας είναι μια ηλεκτρική συσκευή η οποία μετατρέπει το συνεχές ρεύμα των συσσωρευτών σε εναλλασσόμενο. Βασικό κομμάτι του αντιστροφέα είναι η λογική παλμοδότησής του. Ο αντιστροφέας που κατασκευάστηκε χρησιμοποιεί τον άμεσο έλεγχο ροπής, ο οποίος είναι ένα είδος άμεσου διανυσματικού ελέγχου που χρησιμοποιεί τον μετασχηματισμό Park. / Τα τελευταία 35 χρόνια έχει προκύψει ένα ενεργειακό πρόβλημα το οποίο μας επιβάλει να αλλάξουμε την ενεργειακή μας αντίληψη. Το πετρέλαιο αλλά και άλλα ορυκτά καύσιμα έχουν πεπερασμένα αποθέματα και η χρήση τους επιβαρύνει το περιβάλλον. Επίσης γεωπολιτικά συμφέροντα δεν επιτρέπουν την ανεμπόδιστη διανομή του. Μέσα σε αυτό το κλίμα της ενεργειακής απεξάρτησης από τα ορυκτά καύσιμα αναπτύσσονται τα τελευταία χρόνια τα υβριδικά οχήματα. Τα ηλεκτρικά υβριδικά οχήματα είναι ένα μεταβατικό στάδιο από την πετρελαιοκίνηση στην εξ’ ολοκλήρου κίνηση μέσω ηλεκτρισμού από ενεργειακές κυψέλες. Αποτελούνται από έναν συμβατικό κινητήρα εσωτερικής καύσης και μια ηλεκτρική μηχανή, η οποία τροφοδοτείται από συσσωρευτές. Τα υβριδικά οχήματα χωρίζονται σε διάφορες κατηγορίες ανάλογα με τις τεχνολογίες υβριδοποίησης που διαθέτουν και την διάταξη του ηλεκτρομηχανολογικού τους συστήματος. Στόχος της παρούσας διπλωματικής εργασίας (η οποία είναι η συνέχεια δυο προηγούμενων) είναι η προσπάθεια κατασκευής ενός υβριδικού αυτοκινήτου. Για να γίνει αυτό εφικτό απαιτούνται, ένα όχημα το οποίο να μπορεί να δεχθεί εύκολα μηχανολογικές μετατροπές, ένας ηλεκτρικός κινητήρας και συσσωρευτές. Ο ηλεκτρικός κινητήρας ελέγχεται από έναν αντιστροφέα. Ο αντιστροφέας είναι μια ηλεκτρική συσκευή η οποία μετατρέπει το συνεχές ρεύμα των συσσωρευτών σε εναλλασσόμενο. Βασικό κομμάτι του αντιστροφέα είναι η λογική παλμοδότησής του. Ο αντιστροφέας που κατασκευάστηκε χρησιμοποιεί τον άμεσο έλεγχο ροπής, ο οποίος είναι ένα είδος άμεσου διανυσματικού ελέγχου που χρησιμοποιεί τον μετασχηματισμό Park.
45

Controle de torque do motor de indução trifásico para aplicação em chaves eletrônicas de partida suave / Torque control of the three-phase induction motor for soft-starter applications

Dias, Rogério Pinho 15 February 2008 (has links)
Made available in DSpace on 2016-12-12T17:38:31Z (GMT). No. of bitstreams: 1 Resumo - Rogerio Pinho Dias.pdf: 124846 bytes, checksum: 695e36f2af2139d1d4a624a0e573473f (MD5) Previous issue date: 2008-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents a study for implementation of the control of limitation of electromagnetic torque develops for three-phase induction motor in soft-starters applications. The proposed method is based on the electromagnetic torque estimation from the measurement of stator currents and the stator voltages. The related problems to the stator flux estimation by pure integration of the equation of the stator voltages are minimized with use of low pass filters in the place of pure integrators and high pass filter at the analogical input to eliminate the measurement offset error. The amplitude and phase errors resultant of the filtering process are reduced with the use of a factor of correction in the final stage of integration. Gotten experimental results validate the proposed method showing its viability in applications where the objective is to control only the start or stop process of three-phase induction motors and possibility the applications with soft-starter - to any type of load that does not need speed variation in permanent regimen. / Este trabalho apresenta um estudo para implementação de um controle de limitação do torque eletromagnético produzido pelo motor de indução trifásico para aplicação em chaves eletrônicas de partida suave. O método proposto é baseado na estimação do torque eletromagnético através da medição das correntes e tensões estatóricas. Os problemas relacionados à estimação do fluxo estatórico através da integração da força contra eletromotriz são minimizados com a utilização de filtros passa baixa no lugar dos integradores puros e de filtros passa alta nas leituras analógicas das tensões e correntes estatóricas. Os erros de amplitude e fase devidos aos processos de filtragem são reduzidos com a utilização de um fator de correção na etapa final de integração. Resultados experimentais validam o método proposto mostrando a viabilidade de sua aplicação no controle dos processos de partida e parada do motor de indução trifásico, possibilitando assim, a aplicação das chaves eletrônicas de partida suave - a qualquer tipo de carga - que não necessite da variação de velocidade em regime permanente
46

Efeito da prática no controle de torque isométrico em crianças com transtorno de desenvolvimento de coordenação /

Diz, Maria Angélica da Rocha. January 2008 (has links)
Resumo: Durante o período de escolarização, algumas crianças podem apresentar dificuldades na coordenação motora, principalmente em habilidades manuais, e podem ser identificadas como tendo Transtorno do Desenvolvimento da Coordenação (TDC). Existem evidências na literatura que déficits nos mecanismos de controle e precisão para produção de força/torque dos dedos estejam associados às dificuldades motoras nessas crianças. Assim, como a produção de força/torque é essencial para inúmeras atividades da vida diária, o presente estudo teve como objetivo principal investigar o efeito da prática no desempenho de crianças com TDC e com desenvolvimento típico (DT). Participaram do estudo, 24 crianças com idade entre 9 e 10 anos. A tarefa praticada foi a de preensão digital em torque com feedback visual. As crianças foram incentivadas a manter, durante 15 segundos, de forma contínua e constante, 25% do torque voluntário máximo. A prática foi feita durante cinco dias consecutivos, com realização de 15 tentativas por dia. Após a prática com feedback visual, as crianças foram incentivadas a realizar cinco tentativas na condição sem feedback visual. Nestas tentativas, o feedback visual era removido após 5 segundos do início da tentativa. Os resultados demonstraram que nos cinco dias de prática as crianças com DT foram consistentemente mais precisas em manter o controle de torque do que as crianças com TDC. As crianças de ambos os grupos melhoraram o desempenho no decorrer das sessões de prática evidenciado pela redução do coeficiente de variação e da dispersão média do erro...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: During the first years in school, children can show motor coordination difficulties mainly in manual skills and they can be identified as shown Developmental Coordination Disorder (DCD). There is evidence from the literature that deficits in the mechanisms of accuracy and control in the finger production of strength/torque are associated with the motor difficulties of these children. The production of strength/torque is essential for a large number of daily activities so that the effect of practice of grip torque among DCD children and those shown typical development (DT) was the main objective of the present study. Participants were 24 children aged between 9 and 10 years. Children were asked to keep control of torque in a continuous and constant way with visual feedback (25% of maximum voluntary torque) during a period of 15 seconds. Practice was given during five consecutive days with 15 trials per day. After the practice with visual feedback, children were asked to perform five trials without visual feedback. In these trials, feedback was removed five seconds after the start of the trial. The results showed during the five days of practice that children with DT were consistently more accurate in keeping torque control than those with DCD. Children from both groups improved the level of performance as practice took place shown reduction of the coefficient of variation and of error (RMS). In relation to the trials without visual feedback, DCD children were not able to perform at the same level as they did when visual feedback was available...(Complete abstract, click electronic access below) / Orientador: Ana Maria Pellegrini / Coorientador: Cynthia Y. Hiraga / Banca: José angelo Barela / Banca: Márcio Alves de Oliveira / Mestre
47

Estimation en ligne de paramètres de machines électriques pour véhicule en vue d'un suivi de la température de ses composants / Online estimation of electric motors parameters for tracking of its components temperature in automotive applications

Henwood, Nicolas 23 January 2014 (has links)
Afin de rendre compétitifs les véhicules hybrides ou tout électriques, l'amélioration des performances des machines électriques embarquées est primordiale. Dans cette optique, le travail présenté s'intéresse en particulier à l'estimation en ligne des variations de température au sein d'une machine synchrone à aimants permanents. De ce fait, nous proposons d'estimer les paramètres physiques dépendants de la température, à savoir la résistance des enroulements et le flux des aimants. La connaissance des variations de température ou de ces paramètres permet en effet d'éviter une dégradation des performances en adaptant le contrôle en couple et de mettre en place une surveillance thermique autorisant notamment une meilleure disponibilité de la machine, sans risque d'endommagement. Pour répondre à ce double objectif, nous proposons deux observateurs de paramètres basés sur une modélisation réaliste de la machine. Nous établissons donc, en premier lieu, un modèle électrique du moteur qui tient compte de possibles différences entre signaux mesurés et exacts et garantit la robustesse des observateurs aux paramètres mécaniques. Un algorithme d'identification hors ligne des paramètres est proposé pour valider le modèle. Puis, basé sur ce modèle réaliste, les deux observateurs proposés, dit de Luenberger et de Kreisselmeier, estiment respectivement, suivant certaines conditions d'observabilité, le flux et la position pour le premier et un ou plusieurs paramètres parmi la résistance, le flux et l'inductance pour le second. Ces observateurs n'utilisent que les mesures de courant et de tension, ainsi qu'une mesure de position pour l'observateur de Kreisselmeier. Des études théoriques et en simulation sont menées pour valider le fonctionnement des observateurs et appréhender au mieux leurs réglages. En particulier, nous présentons une étude évaluant l'impact du bruit de mesure sur l'observateur de Luenberger afin d'améliorer sa robustesse au bruit sur une large plage de régime. Finalement, l'implémentation des observateurs sur différents bancs d'essais fournit des résultats prometteurs, tant pour l'estimation des paramètres que pour la faisabilité d'estimer les variations de température. / To make hybrid and full electric vehicles competitive, the performance enhancement of the embedded electric motors is essential. For this purpose, the presented work focuses in particular on the online estimation of temperature variations inside a permanent magnet synchronous motor. Therefore, we propose to estimate the temperature dependant parameters, namely the winding resistance and the magnet flux. The knowledge of these parameters or their temperature variations allows indeed to avoid performance degradation by adapting the torque control and makes possible a thermal monitoring, especially for machine availability improvement without risk of damage. Aiming at this double objective, we propose two parameter observers based on a realistic model of the machine. Thus, we first consider an electrical model of the motor that takes account of possible differences between measured and exact signals and ensures robustness to the mechanical parameters. An offline least squares algorithm for parameters identification is proposed to validate the model. Then, based on this realistic model, we design two observers, called Luenberger and Kreisselmeier. According to some observability conditions, the first one estimates the flux and position while the latter estimates one or several parameters among resistance, flux and inductance. These observers use the currents, voltages, and position for the Kreisselmeier observer, as only measurements. Theoretical and simulation studies are conducted on the observers to validate their efficiency and for a better understanding of their setting parameters. In particular, we present a study assessing the measurement noise impact on the Luenberger observer to improve its robustness to noise over a wide speed range. Finally, the implementation of the observers on different test benches provides promising results, both on parameters estimation and on the feasibility of temperature variations estimation.
48

Modely řízení asynchronního motoru / Induction machnine control techniques and models

Vidlák, Michal January 2019 (has links)
This diploma thesis deals with the design of the asynchronous mathematical model, and creation its model in MATLAB Simulink. And by creating different types of asynchronous motor control. At the beginning of the work there are theoretical knowledge about transformation of quantities into coordinates, which are needed for creation of mathematical model and further for machine control. Furthermore, control logarithms are created from these transformed quantities, which can be used to control the torque or engine speed. It is a constant magnetic flux control, scalar control, vector control, and ultimately direct torque control. All derived control algorithms have been tested in MATLAB Simulink. Where were simulations of investigated quantities.
49

FTC řízení průmyslových robotů a jeho aplikace v oblasti broušení / FTC Control in connection with industrial robots

Mimochodek, Martin January 2010 (has links)
This diploma thesis deals with a conception of force-torque control of industrial robot applied on a finishing technology of grinding. This work includes a classification of various force-torque sensors currently available on the market. The practical part of this thesis deals with a setting-up of communication and connection among the force-torque sensor SCHUNK FTC 050-80, PLC Beckhoff CX and industrial robot KUKA KR3. Practical part is further focused on a simple model of grinding, especially the grinding force control in relation to the robot movement.
50

FTC řízení průmyslových robotů a jeho aplikace v oblasti přímého navádění robotu v prostoru / FTC Control in connection with industrial robots for direct guiding in space

Stano, Pavol January 2010 (has links)
Diploma thesis deals with an application of Force-Torque control in connection with industrial robot for direct guiding in space. It contains a summary of different kinds of FT control and various conceptions of robot-sensor connection and a description of Schunk FTC-50. The practical part is focused on the problem of setting-up the communication and setting-up of all devices used in this work, robot movement control to a desired position and compensation of forces and torques in relation to direct guiding in space.

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