Demands for including more functions such as haptic guiding in power steering systems in road vehicles have increased with requirements on new active safety and comfort systems. Active safety systems, which have been proven to have a positive effect on overall vehicle safety, refer to systems that give the driver assistance in more and less critical situations to avoid accidents. Active safety features are going to play an increasingly important roll in future safety strategies; therefore, it is essential that sub systems in road vehicles, such as power steering systems, are adjusted to meet new demands. The traditional Hydraulic Power Assisted Steering, HPAS, system, cannot meet these new demands, due to the control unit's pure hydro-mechanical solution. The Active Pinion concept presented in this thesis is a novel concept for controlling the steering wheel torque in future active safety and comfort applications. The concept, which can be seen as a modular add-on added to a traditional HPAS system, introduces an additional degree of freedom to the control unit. Different control modes used to meet the demands of new functionality applications are presented and tested in a hardware-in-the-loop test rig. This thesis also covers various aspects of hydraulic power assisted steering systems in road vehicles. Power steering is viewed as a dynamic system and is investigated with linear and non-linear modeling techniques. The valve design in terms of area gradient is essential for the function of the HPAS system; therefore, a method involving optimization has been developed to determine the valve characteristic. The method uses static measurements as a base for calculation and optimization; the results are used in both linear and the non-linear models. With the help of the linear model, relevant transfer functions and the underlying control structure of the power steering system have been derived and analyzed. The non-linear model has been used in concept validation of the Active Pinion. Apart from concept validation and controller design of the active pinion, the models have been roven effective to explain dynamic phenomena related to HPAS systems, such as the chattering phenomena and hydraulic lag. / The printed version and the electronic version differ in that the electronic version contains two built in video films (see page 78 and page 89).

Orientador: Jose Geraldo Pena de Andrade / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-04T21:42:36Z (GMT). No. of bitstreams: 1 Sousa_Marcosde_M.pdf: 3823933 bytes, checksum: 53f9dd72cf2dbc7b62e005fc1ab9212c (MD5) Previous issue date: 2005 / Resumo: O Saneamento, visto de modo clássico, tem como principal objetivo garantir ao homem água de boa qualidade e proporcionar adequado destino a seus dejetos, compreendendo suas atividades básicas abastecimento de água e esgotamento sanitário. Hoje, uma cidade, para proporcionar a qualidade de vida necessária aos seus habitantes, deve dispor dos sistemas considerados fundamentais de saneamento: água, esgoto, lixo e drenagem. Com as crises de energia e esgotamento da exploração dos grandes potenciais hidráulicos em nosso país, as energias alternativas passaram a ser tratadas como fontes de suprimentos energéticos. Nos sistemas de saneamento já se explora a energia produzida pelos gases do lixo em aterros sanitários, os gases produzidos pelas estações de tratamento de esgotos e a energia hidráulica dos rios nos sistemas de macrodrenagem. Nos sistemas de abastecimento de água e de coleta, afastamento e tratamento de esgotos existem pequenos potenciais energéticos que podem perfeitamente serem explorados pelas companhias de saneamento. Portanto, o principal objetivo desta dissertação é o estudo desses potenciais hidráulicos, para a geração de energia elétrica, verificando sua viabilidade técnico­econômica-ambiental-social / Abstract: Sanitation, seen in a classical way, has as main goal to assure the human being good quality water and provide appropriate destination to their dejections, including basic activities of water supply and sanitary exhaustion. Nowadays, a city to provide a quality of life necessary to its inhabitants must supply fundamental systems of sanitation: water, sewage, garbage and drainage. With the energy crisis and the exhaustion of exploration of great hydraulic potentials in our country, the altemative energies. passed to be considered as sources of energy supplies. In sanitation systems, we are already exploring the energy produced by garbage gases in landfills, the gases produced by sewage treatment stations and hydraulic energy of the rivers in macrodrainage system. In water supply and collection systems, sewage displacement and treatment, there are small energy potentials that can be perfectly explored by sanitation companies. Therefore, the main goal of this dissertation is the study of those hydraulics potentials, for the generation of electric energy, verifying its technical, economical, environmental and social viability / Mestrado / Recursos Hidricos / Mestre em Engenharia Civil

Orientador: Sérgio Valdir Bajay / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-23T18:35:51Z (GMT). No. of bitstreams: 1 Gomes_ElisadePodesta_M.pdf: 7431510 bytes, checksum: e7a85003e392f6d271fdc2dc2e9db379 (MD5) Previous issue date: 2013 / Resumo: O desenvolvimento de um país exige energia. Ela está presente em diferentes formas ao nosso redor, seja na lâmpada que ilumina o nosso ambiente de trabalho, no combustível dos veículos, ou em todos os processos de produção industrial. Este trabalho foca a geração de energia elétrica proveniente de usinas hidrelétricas através da repotenciação. Repotenciar é o ato de melhorar os parâmetros atuais de uma usina, seja aumentando sua capacidade instalada, ou seu fator de capacidade, seja melhorando o rendimento, ou as características mecânicas/elétricas das suas máquina. A automação também é um fator importante nas repotenciações de hoje. Repotenciar demanda um prazo muito menor do que a construção de uma usina nova, além de não gerar impactos ambientais adicionais e possuir menor custo. As usinas brasileiras estão envelhecendo e precisam passar por algum processo de modernização para manter (ou aumentar) sua geração. Neste trabalho são apresentados os vários tipos de repotenciações possíveis e os componentes envolvidos em uma usina, assim como se estima a capacidade instalada das usinas hidrelétricas brasileiras mais adequadas para uma repotenciação. Exemplos de repotenciações no País e no exterior são discutidos, com destaque para trabalhos realizados pela Andritz Hydro. As barreiras hoje existentes para uma maior difusão do processo de repotenciação no Brasil são analisadas, e possíveis estratégias para eliminar estes obstáculos são propostas / Abstract: The development of a country requires energy. It is present in different forms around us, in the lamp that illuminates our workplace, in the vehicles' fuels, or in all industrial processes. The focus of this study is the electricity generation coming from hydropower plants through rehabilitation. The latter is the act of improving the current parameters of a power station, increasing the plant's installed capacity or capacity factor, or else, improving the machines' efficiency, or their mechanical/electrical characteristics. Automation is also an important factor in rehabilitations nowadays. Rehabilitation demands much less time than building a new power station; besides, it does not generate additional environmental impacts and has lower costs. Brazilian power stations are aging and need to go through modernization processes in order to keep (or increase) their generation. In this study, the possible rehabilitation types and the power plant components involved are presented. It is estimated the installed capacity power for the most adequated hydro power stations in Brazil regarding rehabilitation project. Examples of rehabilitations in the country and abroad are discussed, particularly some of them carried out by Andritz Hydro. The current barriers for a larger diffusion of the rehabilitation process in Brazil are assessed, and possible strategies to eliminate these obstacles are proposed / Mestrado / Planejamento de Sistemas Energeticos / Mestra em Planejamento de Sistemas Energéticos

Future heavy duty vehicles will be designed and manufactured with improved Advanced Driver Assistance Systems, ADAS. When developing ADAS, an accurate model of the vehicle dynamics greatly simplifies the development process. One element integral to the vehicle lateral dynamics and development of ADAS is the steering system. This thesis aims to develop an accurate model of a heavy duty vehicle steering system suitable for simulations. The input to the system is an input torque at the steering wheel and the output is the wheel angle. Physical models of the system components are developed using bond graphs and known relations. Some components are modelled with non-linear inefficiencies and friction of different complexity. Unknown parameters and functions are identified from measurement data using system identification tools such as, for example, linear regression and non-linear grid search. The different subsystems are identified separately to the extent deemed possible. Different model designs are considered, validated, and compared. The advantages and disadvantages of different model choices are discussed. Finally, a non-linear state space model is selected for its high accuracy and efficiency. As this final model can be used to simulate a heavy duty vehicle steering system on a desktop computer faster than real time, it fulfills its purpose.

The purpose of this diploma work is to predict the action of the swirl turbine in a siphonal configuration using the potential energy provided by the river Úpa near the city Jaroměř. The hydraulic predictions of the turbine impellor were based on calculation made using the CFD program Fluent. The measurement of the draft tube and the strength calculations of the turbine blade and spindle are based upon the theories, experiments and finally on the knowledge gained from the test models constructed. The results of this project can be used when considering the viability of a small hydraulic power plant.

This work includes design of the drive hydraulic shears. The objective is to replace diesel-engine for electric motor. There is a description of the machine and its technological shearing process, types of hydraulic drives and their applications. The work includes the design, description and calculation of hydraulic power unit with an electric motor in two versions. Then there is evaluation of alternatives and select one to which they are processed further structural elements.

The aim of this diploma thesis is to create a hydraulic system for water turbine control. The basic dimensioning of the hydraulic elements is included in order to build a functional hydraulic diagram.

The diploma thesis should identify inconsistencies of the small hydraulic power plant Katovice. The fountain water turbine is now running in slower delivery because the original Francis high speed turbine achieved much smaller flow than a Kaplan type turbine. The aim of the thesis is a project of a spiral case and a distributor for the Kaplan turbine, which should work in higher flow and should be run in its optimum. This project will serve as a base for construction of distributor and spiral case for the small hydraulic power plant Katovice.

This work describes the design of a dedicated three-rolls hydraulic bending for Hardox 500 without the possibility of bending sheet metal for the manufacture of pipes. The work will analyze the problem of proposed three-rolls bending, bending technology and creating of the pre-bending, the design of the adjusting hydraulic servo-cylinder, planetary gearboxes with hydraulic motors to drive the bottom rollers, a partial draft of the hydraulic circuit and the complete frame structure of bending machine with its covers.

This diploma thesis deals with the design of the hydraulic puller. Furthermore, the diploma thesis presents the analysis of possible design solutions. It includes processing the selected design of the hydraulic puller with parameters: maximum pushing force 50 kN, speed of work movement 0,05 m.s-1. The analysis by using finite element method (FEM) is made. The next part of thesis includes the design of hydraulic circuit of puller. In the last part of thesis there is the design for replacement of hydraulic puller by mechanical systems.