The purposes of this study were to: 1) evaluate how movement performance of the thumb and fingers were modified during manipulation of objects with and without fluids and 2) to quantify movement performance and accuracy during manipulation of objects, in two different modes of manipulation, i.e., pendulum and inverted pendulum. Twenty young healthy adults (age 24-35) were recruited and performed two predictable cyclic tracking tasks and episodic short-duration precision movement task. No change in movement performance observed in open-loop or episodic tasks. However, in closed-loop task, mode of manipulation (IP versus P) had a significant effect on amplitude consistency (P<0.001), and temporal accuracy (P<0.050).Fluid motion had a significant effect on RMS of index finger contact forces (p < 0.01) in episodic task. In conclusion, fluid motion had no significant effect on movement performance and accuracy. The quality of movement was better in pendulum mode than inverted pendulum movement.

The purposes of this study were to: 1) evaluate how movement performance of the thumb and fingers were modified during manipulation of objects with and without fluids and 2) to quantify movement performance and accuracy during manipulation of objects, in two different modes of manipulation, i.e., pendulum and inverted pendulum. Twenty young healthy adults (age 24-35) were recruited and performed two predictable cyclic tracking tasks and episodic short-duration precision movement task. No change in movement performance observed in open-loop or episodic tasks. However, in closed-loop task, mode of manipulation (IP versus P) had a significant effect on amplitude consistency (P<0.001), and temporal accuracy (P<0.050).Fluid motion had a significant effect on RMS of index finger contact forces (p < 0.01) in episodic task. In conclusion, fluid motion had no significant effect on movement performance and accuracy. The quality of movement was better in pendulum mode than inverted pendulum movement.

This thesis aims to bring clarity to the dimensioning aspects and limiting factors of the modular multilevel converter (MMC). Special consideration is given to the dc capacitors in the submodules as they are a driving factor for the size and weight of the converter. It is found that if the capacitor voltages are allowed to increase by 10% the stored energy must be 21 kJ/MW in order to compensate the capacitor voltage ripple. The maximum possible output power can, however, be increased by injecting a second-order harmonic in the circulating current. A great advantage of cascaded converters is the possibility to achieve excellent harmonic performance at low switching frequencies. Therefore, this thesis also considers the relation between switching harmonics, capacitor voltage ripple, and arm quantities. It is shown that despite subharmonics in the capacitor voltages, it is still possible to achieve periodic arm quantities. The balancing of the capacitor voltages is also considered in further detail. It is found that it is possible to balance the capacitor voltages even at fundamental switching frequency although this will lead to a comparably large capacitor voltage ripple. Therefore, in order to limit the peak-to-peak voltage ripple, it is shown that a predictive algorithm can be used in which the resulting switching frequency is approximately 2–3 times the fundamental frequency. This thesis also presents two new submodule concepts. The first submodule simply improves the trade-off between the switching frequency and capacitor voltage balancing. The second submodule includes the possibility to insert negative voltages which allows higher modulation indices compared to half-bridge submodules. A brief comparison of cascaded converters for ac-ac applications is also presented. It is concluded that the MMC appears to be well suited for ac-ac applications where input and output frequencies are close or equal, such as in interconnection of ac grids. In low-frequency applications such as low-speed drives, however, the difficulties with handling the energy variations in the converter arms are much more severe in the MMC compared to the other considered topologies. / <p>QC 20141010</p>

This thesis focuses on the theory, design, simulation and implementation of several digital controllers for periodic signals on a laser scanning galvanometer. A model for the galvanometer was obtained and veri ed using closed loop identi cation techniques. Using this model, controllers were designed and simulated using MATLAB and then implemented on a custom FPGA control processor with a focus on tracking performance. The types of controllers used were: an Iterative Learning Controller, an RST pole placement controller, an Adaptive Feed-forward cancellation controller, a combined Iterative Learning and Adaptive Feed-forward cancellation controller and a simple PID controller. The simulated results were better than the experimental results because of system noise and modelling uncertainties but the relative performance between each of the controllers was similar for both the simulation and experimental setup. The experimental results achieved were very good with one controller reaching errors under 50 rad. / Graduate / 0537 / t_Torres_bonet@hotmail.com

No description available.

This dissertation is the result of research and development of a power conditioning system for Superconductive Magnetic Energy Storage System. The dominant challenge of this research was to develop the power conditioning system that can match slowly varying dc voltage and dc current on the super conductive magnet side with the ac voltages and ac currents on the utility side. At the same time the power conditioning system was required to provide a bi-directional power flow to the superconductive magnet. The focus of this dissertation is a three-level diode clamped dc-ac converter which is a principle part of the power conditioning system. Accordingly, this dissertation deals with the space vector modulation of three-level converters and introduces a computationally very efficient three-level space vector modulation algorithm that is experimentally verified. Furthermore, the proposed space vector modulation algorithm is successfully generalized to allow equally efficient, real time implementation of space vector modulation to dc-ac converters with virtually any number of levels. The most important advantage of the proposed concept is in the fact that the number of instructions required to implement the algorithm is almost independent from the number of levels in a multilevel converter. More on the side of the control of multilevel converters, the particular attention in this dissertation is paid to the problem of charge balance in the split dc-link capacitors of three-level neutral-point-clamped converters. It is a known fact that although the charge balance in the neutral point can be maintained on a line cycle level, a significant third harmonic current flows into the neutral point for certain loading conditions, causing the neutral point voltage ripple. The logical consequence of that ripple is the deteriorated quality of the output voltage waveforms as well as the increased voltage stress on the switching devices. This was the motivation to more carefully explore the loading conditions that cause the unbalance, as well as to study the fundamental limitations of dc-link capacitor charge balancing algorithms. As a part of that work, a new model of the neutral point current in the rotating coordinate frame is developed as a tool in investigation of theoretical limitations and in providing some intuitive insight into the problem. Additionally, the low frequency ripple is quantified and guidelines are offered that can help size the dc-link capacitors. Because the study of the neutral point balance identified the loading conditions, that under some possible system constraints, cause an unavoidable neutral point voltage ripple, a feed forward type of control method is developed next. The proposed feed forward algorithm can effectively prevent the neutral point voltage ripple from creating distortions in the converter output voltage under all loading conditions and without causing additional disturbance in the neutral point voltage. The feed forward method is developed for a sine triangle as well as for the space vector type PWM algorithm. The simulation results that include the full dynamic model of the converter and load system validate the feed forward approach and prove that the feed forward algorithm can effectively compensate the effect of the neutral point voltage ripple. The simulation results are than experimentally verified. / Ph. D.

Grid-connected high-power converters are found in high-voltage direct current transmission (HVDC), static compensators (STATCOMs), and supplies for electric railways. Such power converters should have a high reliability, high efficiency, good harmonic performance, low cost, and a small footprint. Cascaded converters are promising solutions for high-voltage high-power converters since they allow the combination of excellent harmonic performance and low switching frequencies. A high reliability can also be achieved by including redundant submodules in the chain of cascaded converters. One of the emerging cascaded converter topologies is the modular multilevel converter (M2C). This thesis aims to bring clarity to the dimensioning aspects and limiting factors of M2Cs. The dc-capacitor in each submodule is a driving factor for the size and weight of the converter. It is found that the voltage variations across the submodule capacitors will distort the voltage waveforms and also induce alternating components in the current that is circulating between the phase-legs. It is, however, shown that it is possible to control the alternating voltage by feed-forward control. It is also shown that if the circulating current is controlled, the injection of a second-order harmonic component can extend the operating region of the converter. The reason for this is that when the converter is operating close to the boundary of overmodulation the phase and amplitude of the second-order harmonic is chosen such that the capacitors are charged prior to the time when a high voltage should be inserted by the submodules. The controller that is used must be able to balance the sbmodule capacitor voltages. Typically, an increased switching frequency will enhance the performance of the balancing control scheme. In this thesis it is shown that the capacitor voltages can be balanced with programmed modulation, even if fundamental switching frequency is used. This will, however, increase the voltage ripple across the aforementioned capacitors. In order to quantify the requirements on the dc-capacitors a general analysis is provided in this thesis which is based on the assumption that the capacitor voltages are well balanced. It is found that for active power transfer, with a 50 Hz sinusoidal voltage reference, the capacitors must be rated for a combined energy storage of 21 kJ/MW if the capacitor voltages are allowed to increase by 10% above their nominal values. / <p>QC 20121127</p>

Cieľom práce je aplikácia lokálnych aproximátorov pre riadenie reálnych mechatronických sústav pomocou metódy dopredného riadenia predstavujúcej zaujímavú alternatívu k metódam využívajúcim globálne aproximátory. Po ukážkových príkladoch funkcie lokálnych aproximátorov bol navrhnutý algoritmus implementovaný pre riadenie dvoch sústav, elektronickej škrtiacej klapky a výukového modelu magnetickej levitácie, predstavujúcich vysoko nelineárne a nestabilné sústavy. Skúmali sme, či riadiaci algoritmus bude mať pozitívny vplyv na presnosť regulácie, ďalej bola skúmaná jeho schopnosť prispôsobiť sa zmene parametrov sústavy a tiež prípadná možnosť jeho implementácie pre mikrokontrolér znížením vzorkovacej frekvencie. Výsledky ukázali, že riadenie založené na lokálnych modeloch zlepšilo riadenie v porovnaní s jednoduchým PID regulátorom a že má schopnosť adaptability. Veľmi výhodné sa zdá byť jeho použitie pre zariadenia umožnujúce vzorkovaciu frekvenciu do 1 kHz.

Verdrängergesteuterte hydrostatische Antriebssysteme mit drehzahlvariablem Pumpenantrieb zeichnen sich durch ihre im Vergleich mit ventilgesteuerten Antrieben gute Energieeffizienz und die Möglichkeit der einfachen Stillsetzung aus, weisen jedoch durch die mangelnde Einspannung des Aktors geringere Eigenfrequenzen auf, was die Einstellung von Standardregelkreisen erschwert und meist eine geringere Dynamik und Positioniergenauigkeit zur Folge hat. Hydraulische Achsantriebe, die ohnehin über zahlreiche dominante Nichtlinearitäten verfügen und schwach gedämpft sind können in der Folge das ihnen innewohnende Potential nicht ausschöpfen. Mit einem Vergleich von Dynamik und Präzision verschiedener Antriebssysteme an Hauptantriebsachsen von Kunststoff-Spritzgießmaschinen mittlerer Baugröße wird zunächst das Leistungspotential analysiert. Auf dieser Basis werden Methoden zur Verbesserung der statischen und dynamischen Eigenschaften drehzahlvariabler verdrängergesteuerter Antriebe in Positions- und Druckregelung entwickelt, welche sich durch eine einfache Parametrierung und hohe Robustheit auszeichnen, da sie ohne einen geschlossenen Regelkreis funktionieren. Die dynamische inversionsbasierte Vorsteuerung ermöglicht dabei ein initial gutes Folgeverhalten, das durch die Anwendung einer iterativ lernenden Regelung in jedem Zyklus weiter verbessert wird. Um die Dynamik von Folgeregelungen mit weiteren Randbedingungen zu maximieren wird eine Methode entwickelt, mit der es möglich ist, eine Bewegungsvorgabe entlang der physikalischen Leistungsgrenzen des Antriebssystems zu berechnen und die wirkenden Begrenzungen aufzuzeigen. Die Erstellung von Bewegungsvorgaben sowie die Einstellung der lernenden Regelung sind dabei jeweils mit einem einzigen Parameter möglich. Die experimentelle Untersuchung und der Funktionsnachweis der entwickelten Methoden am Beispiel der Kunststoff-Spritzgießmaschine zeigt eine deutliche Steigerung der möglichen Dynamik verdrängergesteuerter Antriebssysteme, ein gutes Folgeverhalten sowie eine erhöhte Positioniergenauigkeit bei gleichzeitiger Unabhängigkeit von der Betriebstemperatur.:1. Einleitung und wissenschaftliche Problemstellung 7 2. Zielsetzung der Arbeit 11 3. Stand der Forschung und Technik 13 3.1 Architekturen hydraulischer Linearantriebe 13 3.2 Betriebsverhalten drehzahlvariabler verdrängergesteuerter Antriebe 16 3.3 Regelung hydraulischer Achsantriebe in Verdrängersteuerung 18 3.4 Vorsteuerungen und iterativ lernende Regelungen 21 4. Antriebstechnik in Kunststoff-Spritzgießmaschinen 25 5. Analyse der Leistungsfähigkeit von Antriebssystemen in SGM 27 5.1 Aufbau und Funktionsweise von Spritzgießmaschinen 28 5.2 Auswahl der Antriebssysteme 31 5.3 Analyse der Bewegungsdynamik 34 5.4 Analyse der Positioniergenauigkeit 37 5.5 Analyse der Druckregelung 39 5.6 Identifikation von Potentialen für die Leistungssteigerung 44 6. Trajektoriengenerierung entlang der Systemleistungsgrenzen 47 6.1 Kniehebel-Schließeinheit 48 6.2 Analyse statischer und dynamischer Restriktionen 50 6.3 Trajektorienentwurfsmethodik 59 7. Modellbasierte dynamische Vorsteuerung 67 7.1 Methodik 68 7.2 Mathematisch-physikalische Beschreibung 69 7.3 Inversionsbasiertes Steuergesetz 75 8. Modellbasierte lernende Vorsteuerung 77 8.1 Methodik 78 8.2 Entwurf modellbasierter normoptimaler iterativ lernender Regelungen 79 8.3 Stabilitätsnachweis 84 8.4 Generierung von Lernmodellen 86 9. Anwendung der Verfahren und Diskussion 91 9.1 Positionsregelung im geschlossenen hydrostatischen Kreis 93 9.2 Lastkraftregelung im offenen Kreis 108 9.3 Ablösende Regelung: Geschwindigkeit - Last 123 10. Zusammenfassung 127 11. Literatur 133 12. Anhang 145 / Displacement-controlled hydrostatic drive systems with variable-speed pump are characterized by their good energy efficiency and the possibility of simple shutdown compared with valve-controlled drives, but they have lower natural frequencies, which makes the application of standard closed-loop control more difficult and usually results in lower dynamics and positioning accuracy. As a result hydraulic drives, which already have numerous dominant nonlinearities and are weakly damped, cannot exploit their full potential. The work starts with a comparison and an analysis of the dynamics and precision of different drive systems on main drive axes of medium-size plastic injection molding machines. On this basis, methods are developed for improving the static and dynamic properties of variable-speed displacement-controlled drives in position and pressure control. These methods are characterized by simple parameterization and high robustness without relying on a closed-loop control. In this context, the dynamic inversion-based feedforward control allows for a good tracking performance, which is further improved by applying a cycle-wise iterative learning control. In order to fulfill the dynamics of follow-up control with position boundary conditions, a method is developed which allows for calculating a motion specification along the physical performance limits of the drive system and to show the existing limitations. The creation of motion presets as well as the setting-up of a learning controller may be done with one single parameter. Experimental investigation of the developed methods using the example of the plastic injection molding machine shows a significant increase in dynamics of displacement-controlled drive systems, good follow-up behavior, and increased positioning accuracy while remaining independent of the operating temperature.:1. Einleitung und wissenschaftliche Problemstellung 7 2. Zielsetzung der Arbeit 11 3. Stand der Forschung und Technik 13 3.1 Architekturen hydraulischer Linearantriebe 13 3.2 Betriebsverhalten drehzahlvariabler verdrängergesteuerter Antriebe 16 3.3 Regelung hydraulischer Achsantriebe in Verdrängersteuerung 18 3.4 Vorsteuerungen und iterativ lernende Regelungen 21 4. Antriebstechnik in Kunststoff-Spritzgießmaschinen 25 5. Analyse der Leistungsfähigkeit von Antriebssystemen in SGM 27 5.1 Aufbau und Funktionsweise von Spritzgießmaschinen 28 5.2 Auswahl der Antriebssysteme 31 5.3 Analyse der Bewegungsdynamik 34 5.4 Analyse der Positioniergenauigkeit 37 5.5 Analyse der Druckregelung 39 5.6 Identifikation von Potentialen für die Leistungssteigerung 44 6. Trajektoriengenerierung entlang der Systemleistungsgrenzen 47 6.1 Kniehebel-Schließeinheit 48 6.2 Analyse statischer und dynamischer Restriktionen 50 6.3 Trajektorienentwurfsmethodik 59 7. Modellbasierte dynamische Vorsteuerung 67 7.1 Methodik 68 7.2 Mathematisch-physikalische Beschreibung 69 7.3 Inversionsbasiertes Steuergesetz 75 8. Modellbasierte lernende Vorsteuerung 77 8.1 Methodik 78 8.2 Entwurf modellbasierter normoptimaler iterativ lernender Regelungen 79 8.3 Stabilitätsnachweis 84 8.4 Generierung von Lernmodellen 86 9. Anwendung der Verfahren und Diskussion 91 9.1 Positionsregelung im geschlossenen hydrostatischen Kreis 93 9.2 Lastkraftregelung im offenen Kreis 108 9.3 Ablösende Regelung: Geschwindigkeit - Last 123 10. Zusammenfassung 127 11. Literatur 133 12. Anhang 145

Les technologies avancées de semi-conducteur permettent de mettre en œuvre un contrôleur numérique dédié aux convertisseurs à découpage, de faible puissance et de fréquence de découpage élevée sur FPGA et ASIC. Cette thèse vise à proposer des contrôleurs numériques des performances élevées, de faible consommation énergétique et qui peuvent être implémentés facilement. En plus des contrôleurs numériques existants comme PID, RST, tri-mode et par mode de glissement, un nouveau contrôleur numérique (DDP) pour le convertisseur abaisseur de tension est proposé sur le principe de la commande prédictive: il introduit une nouvelle variable de contrôle qui est la position de la largeur d'impulsion permettant de contrôler de façon simultanée le courant dans l'inductance et la tension de sortie. La solution permet une dynamique très rapide en transitoire, aussi bien pour la variation de la charge que pour les changements de tension de référence. Les résultats expérimentaux sur FPGA vérifient les performances de ce contrôleur jusqu'à la fréquence de découpage de 4MHz. Un contrôleur numérique nécessite une modulation numérique de largeur d'impulsion (DPWM). L'approche Sigma-Delta de la DPWM est un bon candidat en ce qui concerne le compromis entre la complexité et les performances. Un guide de conception d'étage Sigma-Delta pour le DPWM est présenté. Une architecture améliorée de traditionnelles 1-1 MASH Sigma-Delta DPWM est synthétisée sans détérioration de la stabilité en boucle fermée ainsi qu'en préservant un coût raisonnable en ressources matérielles. Les résultats expérimentaux sur FPGA vérifient les performances des DPWM proposées en régimes stationnaire et transitoire. Deux ASICs sont portés en CMOS 0,35µm: le contrôleur en tri-mode pour le convertisseur abaisseur de tension et la commande par mode de glissement pour les convertisseurs abaisseur et élévateur de tension. Les bancs de test sont conçus pour conduire à un modèle d'évaluation de consommation énergétique. Pour le contrôleur en tri-mode, la consommation de puissance mesurée est seulement de 24,56mW/MHz lorsque le ratio de temps en régime de repos (stand-by) est 0,7. Les consommations de puissance de command par mode de glissement pour les convertisseurs abaisseur et élévateur de tension sont respectivement de 4,46mW/MHz et 4,79mW/MHz. En utilisant le modèle de puissance, une consommation de la puissance estimée inférieure à 1mW/MHz est envisageable dans des technologies CMOS plus avancées. Comparé aux contrôlés homologues analogiques de l'état de l'art, les prototypes ASICs illustrent la possibilité d'atteindre un rendement comparable pour les applications de faible et de moyen puissance mais avec l'avantage d'une meilleure précision et une meilleure flexibilité. / Owing to the development of modern semiconductor technology, it is possible to implement a digital controller for low-power high switching frequency DC-DC power converter in FPGA and ASIC. This thesis is intended to propose digital controllers with high performance, low power consumption and simple implementation architecture. Besides existing digital control-laws, such as PID, RST, tri-mode and sliding-mode (SM), a novel digital control-law, direct control with dual-state-variable prediction (DDP control), for the buck converter is proposed based on the principle of predictive control. Compared to traditional current-mode predictive control, the predictions of the inductor current and the output voltage are performed at the same time by adding a control variable to the DPWM signal. DDP control exhibits very high dynamic transient performances under both load variations and reference changes. Experimental results in FPGA verify the performances at switching frequency up to 4MHz. For the boost converter exhibiting more serious nonlinearity, linear PID and nonlinear SM controllers are designed and implemented in FPGA to verify the performances. A digital control requires a DPWM. Sigma-Delta DPWM is therefore a good candidate regarding the implementation complexity and performances. An idle-tone free condition for Sigma-Delta DPWM is considered to reduce the inherent tone-noise under DC-excitation compared to the classic approach. A guideline for Sigma-Delta DPWM helps to satisfy proposed condition. In addition, an 1-1 MASH Sigma-Delta DPWM with a feasible dither generation module is proposed to further restrain the idle-tone effect without deteriorating the closed-loop stability as well as to preserve a reasonable cost in hardware resources. The FPGA-based experimental results verify the performances of proposed DPWM in steady-state and transient-state. Two ASICs in 0.35µm CMOS process are implemented including the tri-mode controller for buck converter and the PID and SM controllers for the buck and boost converters respectively. The lab-scale tests are designed to lead to a power assessment model suggesting feasible applications. For the tri-mode controller, the measured power consumption is only 24.56mW/MHz when the time ratio of stand-by operation mode is 0.7. As specific power optimization strategies in RTL and system-level are applied to the latter chip, the measured power consumptions of the SM controllers for buck converter and boost converter are 4.46mW/MHz and 4.79mW/MHz respectively. The power consumption is foreseen as less than 1mW/MHz when the process scales down to nanometer technologies based on the power-scaling model. Compared to the state-of-the-art analog counterpart, the prototype ICs are proven to achieve comparable or even higher power efficiency for low-to-medium power applications with the benefit of better accuracy and better flexibility.