The purpose of the project is to implement a control system for a 3- axis camera stabilizer. The stabilization is done by controlling three blushless DC motors driving the yaw, pitch and roll movements of the camera stabilizer's frame, respectively. The stabilizer's frame (equipped with three motors) is used in this project, and it is directly taken from a commercial product, Feiyu Tech G4S. The control system concerned in this project consists of a Teensy 3.6 microcontroller unit (MCU) implemented with three PID controllers, the motor drivers to drive the three motors, and an inertial measurement unit (IMU) of 9 degrees of freedom.The MCU is also used to process the IMU angle measurements of the camera position in 3- axis motion, in particular, it converts the IMU raw data to an angle for each of the axis, it then processes the angle data using a Kalman filter to reduce the noise. In the end of the project a prototype has been built and tested, it uses the control system to run the stabilizing process. It is shown to work quite successfully. In particular, it can run smoothly in the roll and pitch axes and compensate for unwanted movement, however the yaw axis does not function as intended due to a misplacement as well as poor calibration process of the magnetometer sensor in the IMU, which is left for future work.

A presente dissertação tem como objetivo estudar e aprimorar métodos de projetos de controladores para sistemas de potência, sendo que esse trabalho trata da estabilidade dinâmica de sistemas de potência e, portanto, do projeto de controladores amortecedores de oscilações eletromecânicas para esses sistemas. A escolha dos métodos aqui estudados foi orientada pelos requisitos que um estabilizador de sistemas de potência (ESP) deve ter, que são robustez, descentralização e coordenação. Sendo que alguns deles tiveram suas características aprimoradas para atender a esses requisitos. A abordagem dos métodos estudados foi restringida à análise no domínio tempo, pois a abordagem temporal facilita a modelagem das incertezas paramétricas, para atender ao requisito da robustez, e também permite a formulação do controle descentralizado de maneira simples. Além disso, a abordagem temporal permite a formulação do problema de projeto utilizando desigualdades matriciais lineares (LMI’s), as quais possuem como vantagem o fato do conjunto solução ser sempre convexo e a existência de algoritmos eficientes para o cálculo de sua solução. De fato, existem diversos pacotes computacionais desenvolvidos no mercado para o cálculo da solução de um problema de inequações matriciais lineares. Por esse motivo, os métodos de projeto para controladores de saída buscam sempre colocar o problema na forma de LMI’s, tendo em vista que ela garante a obtenção de solução, caso essa solução exista. / The current work aims to study and improve the power system controllers design methods. And we are interested in the dynamic stability of power systems, and thus, in the design of electromechanical oscillations damping controllers. The design methods studied here were chosen to fill the requirements that a power system stabilizer (PSS) must obey, that are robustness, decentralization and coordination. And the characteristics of some of these methods were improved and extended in order to meet these requirements. The approach of the studied methods is restricted to the time domain analysis because of the easiness to model the parametric uncertainties, to meet the robustness requirement, and because it also simplifies the formulation of the decentralized control problem. Moreover the time domain approach allows one to use linear matrix inequalities (LMI’s) to formulate the design problem, which has the advantages that the solution set is always convex, and that there exists efficient algorithms to compute its solution. There are several software packages developed, in the market, to solve the problem of linear matrix inequality. So that the design methods using output controllers always try to formulate this problem in the form of an LMI, because it guarantees that one can obtain a solution for the problem, in the case that this solution exists.

Orientador : Reginaldo Palazzo Junior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T00:27:05Z (GMT). No. of bitstreams: 1 Almeida_AntonioCarlosAidode_D.pdf: 2149041 bytes, checksum: 427f77a8e0ec2774c7b152dd209ba9fa (MD5) Previous issue date: 2004 / Resumo: A decoerencia é um dos maiores desafios obstrutivos da computação quantica. Os codigos corretores de erros quanticos tem sido desenvolvidos com o intuito de enfrentar este desafio. Uma estrutura de grupos e uma classe associada de codigos, a classe dos codigos estabilizadores, tem-se mostrado uteis na produção de codigos e no entendimento da estrutura de classes de codigos. Todos os codigos estabilizadores descobertos ate o momentos são codigos de bloco. Nesta tese, construiremos uma classe de codigos convolucional quanticos concatenados. Introduziremos o conceito de memoria convolucional quantica e algumas tecnicas simples para produzir bons codigos convolucionais quanticos a partir de classes de codigos concolucionais classicos / Abstract: Decoherence is one of the major challenges facing the field of quantum computation. The field of quantum error correction has developed to meet this challenge. A group-theoretical structure and associated class of quantum codes, the stabilizer codes, has proved particularly fruitful in producing codes and in understanding the structure of both specified codes and class of codes. All stabilizer codes discovered so far are block codes. In this thesis we will construct a class of concatenated quantum convolutional codes. We will introduce the concept of quantum convolutional memory and some simple techniques to produce good quantum convolutional codes from classes of classical convolutional codes / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica

This work reports the outdoor weathering performance of ultraviolet (UV)-stabilized polypropylene (PP) products (using PP resins from Encore Wire). Different hindered amine light stabilizers (HALSs) and nano-ZnO were used to stabilize PP-film-based formulations that were exposed under UV light for 6 weeks simulating for in harsh outdoor weather of Dallas, Texas, USA in 2016. Characterization of the exposed PP film products was done in terms of mechanical and friction spectroscopic properties. The PP film formulations were divided into 15 categories based on the type of HALS and nano-ZnO incorporated. This was done to derive meaningful comparison of the various film formulations. Following exposure under UV light, the lifetimes of certain formulations were determined. On the basis of the mechanical and friction properties, it was determined that generally, the HALS or nano-ZnO stabilized PP film give better properties and if those two kinds of UV stabilizers can work together.

This diploma thesis deals with the measurement of the torsion stabilizer characteristics. The beginning of the thesis explains the function of a torsion stabilizer in a vehicle and introduces various technical options of stabilization. Next part is focused on computational simulation of representative stabilizers. Next parts are devoted to proposition of measuring device for torsion stabilizers in the laboratory and execution of the experiment. In the final part multibody model is created to demonstrate achieved results.

My thesis will be aimed at front axle design. I am going to design the assembly of the front axle in the program ADAMS by MSC. I am going to observe and record most of cinematic changes of the car such as change of position of vehicle roll centre ,wheel camber, geometry adjustment , wheel toe-in measuring and other necessary data. The final report is going to include strength calculation of particular axle parts. I am also going to solve the axle stabilizer including strength calculation.

This Master´s thesis describes the design of composite horizontal tail of VUT 100 aircraft. Load calculation and selection of the critical load cases is performed. Internal structure of stabilizer and right elevator is designed. Construction materials are chosen and the structure of the composite materials is proposed. FEM models of stabilizer and the right elevator are created in MSC Patran system and consequently the strength test of the models for the selected load cases is executed using MSC Nastran software and COMPOST.

Platinautvinning är antagligen en av the farligaste gruvindustrierna. På följd av det har gruvmaskiner som Slotborer utvecklats för att göra utvinningsprocessen säkrare. Slotborern är ett ganska nytt koncept och har problem med vibrationer i borrsträngen när den blir längre.Den här rapporten föreslår fyra koncept för att dämpa/stabilisera dessa vibrationer och ett av dessa koncept var sedan vidare utvecklat efter en evaluering. Det koncept som vidareutvecklats använder sig av massdämpare för att dämpa/stabilisera borrsträngen. Massdämparna är justerbara vilket gör dem effektiva över ett större frekvensområde. Några mätvärden från riktiga borrningar var analyserade och analytiska och matematiska modeller var utvecklade att ha ett liknande beteende som det från mätningarna. Modellerna var sedan utvidgade och massdämparna var implementerade in i modellerna för att analysera deras effekt på systemet. När de analytiska modellerna för massdämparna vara klara nog, började konstruktions- och dimensioneringsarbetet av projektet. Dämparen/stabilisatorn var från början konstruerad för att direkt dämpa vibrationer på 2 – 5 Hz, men på grund av väldigt höga spänningar i massdämparna var frekvensspannet ändrat till 3,5 – 6-7 Hz. Ingen verifiering genom empiriska studier var gjorda men några bra analytiska resultat åstadkoms. / Platinum excavation is probably one of the most dangerous mining businesses. Because of that machines like the Slotborer has been developed to make the excavation process much safer. The Slotborer is a pretty new concept and has problems with oscillations in the drill string when it gets extended.This paper suggests four concepts for dampening/stabilizing these oscillations and one of these concepts was then further developed after an evaluation. The further developed concept uses mass dampers to dampen/stabilize the drill string. The mass dampers are adjustable making them effective for a wider range of frequencies. Some measurements from actual drilling operations was analyzed and analytical and mathematical models were developed to have a similar behavior of that from the measurements. The models was then extended and the mass dampers was applied into the models to analyze their impact of the system. When the analytical models for the mass dampers where done enough, the construction and dimensioning of the project took place. The damper/stabilizer was initially design to directly dampen oscillations between 2 – 5 Hz, but due to very high stresses in the mass dampers the dampening frequency span was changed to 3,5 – 6,7 Hz. No verification through empirical studies was made but some good analytical results of damping was achieved.

The issue of descaling is an important part of the forging and heat treatment of steel and semi products of steel production. Rising of new information and study of this process can increase efficiency and improve the surface quality after descaling. This thesis is focused on the mechanisms of the high pressure hydraulic descaling qualification and study of the chemical compounds of which the scales grown. To achieve all goals of this work and to get a comprehensive view of descaling process, few experimental measurements and numerical analyses were performed. All experimental measurements were focused on obtaining data about fundamental parameters and effects of the hydraulic descaling. The data obtained from measurements were applied to numerical analyses, which aimed to discover a deeper relation and to confirm the experimental results. This thesis can be divided into two main parts. The first part is devoted to parameters of the water jet study. The main studied characteristics of the high pressure hydraulic water jet were heat transfer coefficient and impact pressure at different modes such as standard or pulsating water jet. Experimentally measured data of these parameters were applied in numerical analyses. The numerical analyses were focused on studying the impact of the water jet parameters on the stresses in the oxide scale layers. A further water jet analysis was focused on the influence of the individual parts of the hydraulic system (such as water chamber or stabilizer) on its characteristics. In this part different types of the water chambers in combination with different types of stabilizers on the impact pressure values were investigated. These measurements were supported by fluid flow analysis through the hydraulic system. The second part of this work was focused on getting mechanical properties of the oxide scales from specimens prepared from standard structural steel and specimens from silicon steel. In this thesis, the influence of various parameters and characteristics was studied on these two types of steel. Mechanical properties of oxide scale structures were carried out by the Small Punch Test method. To obtain the fundamental mechanical properties such as Young´s modulus, yield strength and ultimate strength, material parameters based on the measured data were optimized. The whole work was carried out in order to get valuable and comprehensive results about high pressure hydraulic descaling process and influencing factors as well as about oxide scales themselves.

Une partie symétrique X d'un groupe G est un sous-groupe K-approximatif s'il existe une partie finie E ⊂ G de taille K telle que X2 ⊂ E.X. L'étude combinatoire des groupes approximatifs a grandement bénéficié des apports de la Théorie des Modèles : en 2009, Hrushovski montre qu'une ultralimite de groupes approximatifs finis possède une composante connexe modèle-théorique, donc un quotient localement compact X/H. En appliquant les résultats de Gleason et Yamabe sur le cinquième problème de Hilbert, cela permet de trouver un morphisme vers un groupe de Lie, et d'en déduire des résultats de nilpotence. Cela a permis à Breuillard, Green et Tao de classifier tous les groupes approximatifs finis, en retrouvant un quotient X/H de manière combinatoire. Dans cette thèse, on s'intéresse à la construction d'un sous-groupe H type-définissable et d'indice borné, qui garantit l'existence d'un quotient localement compact. On montre que l'approche combinatoire de Breuillard, Green et Tao peut être vue de cette manière, et on la généralise à tous les groupes approximatifs définissablement moyennables. On montre aussi que si H est type-définissable dans un langage L∗, alors on peut construire un sous-groupe H qui est type-définissable sur un langage réduit L, et toujours d'indice borné. L'existence de H ne dépend donc pas du choix du langage / A symmetric subset X in a group G is a K-approximate subgroup if there exists a finite set E ⊂ G of cardinality K such that X2 ⊂ E.X. The study of approximate subgroups in multiplicative combinatorics experienced a significate advance through the use of model theory. In 2009, Hrushovski showed that an ultralimit of finite approximate subgroups has a model-theoretic connected component, thus a locally compact quotient X/H. Using the results of Gleason and Yamabe about Hilbert’s fifth problem, this allows the construction of a morphism to a Lie group, and deduce some results about nilpotency. This lead to the theorem of Breuillard, Green and Tao classifying all finite approximate subgroups, using a combinatorial construction of the quotient X/H. In this thesis, we are intersested in the conditions needed to construct a type definable subgroup H of bounded index in X. This implies the existence of a locally compact quotient.We show that the combinatorial construction of Breuillard, Green and Tao can be seen in a definable way, and give a generalisation to all definably amenable approximate subgroups. Also, we show that if H is type-definable in a language L∗, then it is possible to construct a subgroup H which is type-definable in a reduct L, still with bounded index. Thus the existence of a subgroup H does not depend on the choice of a base language.