Exoskeletons and humanoid robots require high-power, low-weight, and back-driveable actuators. This paper describes the design and analysis of a high-force linear series elastic actuator for a lower body exoskeleton. The actuator is powered by two motors and utilize a liquid cooling system to increase its maximum continuous torque. The actuator is capable of outputting a maximum continuous force of 4800N and a maximum speed of 0.267 m/s with a maximum continuous motor current of 18A. The Titanium leaf spring was used in the actuator to provide compliance. The spring has a median stiffness of 587 N/mm with standard deviation of 38 N/mm, validated by experiments. Dynamic model was created to analyze the normal modes and can be used for developing model-based controllers. / Master of Science / Compliant Linear actuators with ball screw have become popular for humanoids robots and exoskeleton. The use of ball screw lead to high efficiency, high gear ratio and high back-drivability. The compliance or the ''softness'' of the actuator comes from Titanium leaf spring, which can storage energy during gait cycle and protect motor and the ball screw from impacts of walking. The custom liquid cooling system improves the force density for the actuator. Beam theory analysis, heat transfer analysis, and dynamics analysis were performed to provides insights for the actuator system.

Abstract In Paper [I], I develop the FOR-DICE model to analyze optimal global forest carbon management. The FOR-DICE is a simple framework for assessing the role of the boreal, tropical, and temperate forests as both a source of renewable energy and a resource to sequester and store carbon. I find that forests play an important role in reducing global emissions, especially under ambitious climate targets. At the global level, efforts should focus on increasing the stock of forest biomass rather than increasing the use of the forest for bioenergy production. The results also highlight the important role of reducing tropical deforestation to reduce climate change. In Paper [II], I develop the FRICE to investigate the role of two key efforts to increase the stock of forest biomass, namely, afforestation and avoided deforestation. FRICE is a multi-regional integrated assessment model that captures the dynamics of forest carbon sequestration in a transparent way and allows me to investigate the allocation of these actions across space and time. I find that global climate policy can benefit considerably from afforestation and avoided deforestation in tropical regions, and in particular in Africa. Avoided deforestation is particularly effective in the short run while afforestation provides the largest emissions reductions in the medium run. This paper also highlights the importance of not solely relying on avoided deforestation as its capacity to reduce emissions is more limited than afforestation, especially under more stringent temperature targets. In Paper [III], we investigate how uncertainties linked to the forest affect the optimal climate policy. We incorporate parameter uncertainty on the intrinsic growth rate and climate effects on the forest by using the state-contingent approach. Our results show that forest uncertainty matters. We find that the importance of including forest in climate policy increases when the forest is subject to uncertainty. This occurs because optimal forest response allows us to reduce the costs associated with uncertainty. In Paper [IV], we explore the implications of asymmetries in climate policy arising from not recognizing forest carbon emissions and sequestration in the decision-making process. We show that not fully including carbon values associated with the forest will have large effects on different forest controls and lead to an increase in emissions, higher carbon prices, and lower welfare.  We further find, by investigating the relative importance of forest emissions compared to sequestration, that recognizing forest emissions from bioenergy and deforestation is especially important for climate policy.

This article describes the development of a component-based technology robot system that can be rapidly configured to perform a specific manufacturing task. The system is conceived with standard and inter-operable components including actuator modules, rigid link connectors and tools that can be assembled into robots with arbitrary geometry and degrees of freedom. The reconfigurable "plug-and-play" robot kinematic and dynamic modeling algorithms are developed. These algorithms are the basis for the control and simulation of reconfigurable robots. The concept of robot configuration optimization is introduced for the effective use of the rapidly reconfigurable robots. Control and communications of the workcell components are facilitated by a workcell-wide TCP/IP network and device level CAN-bus networks. An object-oriented simulation and visualization software for the reconfigurable robot is developed based on Windows NT. Prototypes of the robot systems configured to perform 3D contour following task and the positioning task are constructed and demonstrated. Applications of such systems for biomedical tissue scaffold fabrication are considered. / Singapore-MIT Alliance (SMA)

The thermal control of a die is crucial for the development of high efficiency injection moulds. For successful thermal management, this research provides an effective control strategy to find sensor locations, identify thermal dynamic models, and design controllers. By applying a clustering method and sensitivity analysis, sensor locations are identified. The neural network and finite element analysis techniques enable the modeling to deal with various cycle-times for the moulding process and uncertain dynamics of a die. A combination of off-line training through finite element analysis and training using on-line learning algorithms and experimental data is used for the system identification. Based on the system identification which is experimentally validated using a real system, controllers are designed using fuzzy-logic and self-adaptive PID methods with backpropagation (BP) and radial basis function (RBF) neural networks to tune control parameters. Direct adaptive inverse control and additive feedforward control by adding direct adaptive inverse control to self-adaptive PID controllers are also provided. Through a comparative study, each controller’s performance is verified in terms of response time and tracking accuracy under different moulding processes with multiple cycle-times. Additionally, the improved cooling effectiveness of the conformal cooling channel designed in this study is presented by comparing with a conventional straight channel.

There is a need for smaller and more economic transportation systems. Two-wheeled inverted-pendulum machines, such as the Segway, have been proposed to address this need. However, the Segway places the operator on top of a naturally unstable platform that is stabilized by means of a control system. The control stability of the Segway can be severely affected when minor disturbances or unanticipated conditions arise. In this thesis, a dynamic model of a Segway is developed and used in simulations of various conditions that can arise during normal use. The dynamic model of a general two-wheeled inverted pendulum and human rider is presented. Initial estimates of the parameters were calculated or obtained from other references. The results from numerous experiments are presented and used to develop a better understanding of the dynamics of the vehicle. The experimental data was then used to adjust the model parameters to match the dynamics of a real Segway Human Transporter. Finally, the model was used to simulate various failure conditions. The simulations provide a better understanding of how these conditions arise, and help identify which parameters play an important role in their outcome.

No description available.

Lakštinėse spausdinimo mašinose spausdinant spalvotus atvaizdus svarbu mašinos atskirose sekcijose atspaudų sutapimą išlaikyti šimtųjų milimetro dalių tikslumu. Be to, spausdinamų atvaizdų geometrinis nesutapimas abiejose lapo pusėse neturi viršyti 0,1 mm. Viena iš pagrindinių nesutapimo priežaščių yra mechaninio krumpliaratinio perdavimo mechanizmo iš vienos sekcijos į kitą sukamieji virpesiai, kuriuos sukelia krumpliaračių paklaidos ir pasipriešinimo momentų pokyčiai tarp ofsetinių ir forminių cilindrų. Darbe analiziniu – kompiuteriniu būdu nagrinėjama šių virpesių įtaka lapo perdavimo tikslumui. Konkrečiam tyrimui pasirinkta „Heidelberg“ spausdinimo mašina GTO 52, tačiau darbe taikoma tyrimo metodika tinka ir kitoms mašinoms. Sudarytas elektros pavara valdomo lapų perdavimo mechanizmo dinaminis modelis su 16 laisvės laipsnių. Sistemos matematinis modelis (virpesių lygtys ir struktūrinė schema) sudarytas kompiuterizuotu būdu MATLAB/SIMULINK programų terpėje, kurioje atliktas sistemoje vykstančių dinaminių procesų modeliavimas. Pavaroje kylančios paklaidos apibūdinamos sukamųjų virpesių amplitudinėmis – dažninėmis charakteristikomis. Nagrinėjama šių charakteristikų pobūdžio, rezonansinių virpesių ir jų dažnių įtaka lapo perdavimo paklaidos dydžiui. / It is important in printing machines to maintain very high print quality (hundredths of a millimeter) in printing colorful prints. Also mismatches of prints in both sides of sheet must not exceed 0,1 millimeter. One of the reasons of mismatching is mechanical gear transfers mechanisms, from one printing unit to another, rotational oscillations, which are generated by gear errors and resistance moment changes between offset and print cylinder. These oscillations influence to sheet transfer accuracy are examined in analytical – computer way. For particular examination there was selected “Heidelberg” printing press GTO 52, but the examination method can be used for other presses. There was formed dynamic model with 16 degrees of freedom. Mathematical model of the system (oscillation equations and flowchart) was formed with MATLAB/SIMULINK program, in which dynamical process modeling was done. Errors in drive described as an amplitude frequency response. There was examined these response nature, resonant oscillations and its frequency influence to sheets transfer errors size.

The thermal control of a die is crucial for the development of high efficiency injection moulds. For successful thermal management, this research provides an effective control strategy to find sensor locations, identify thermal dynamic models, and design controllers. By applying a clustering method and sensitivity analysis, sensor locations are identified. The neural network and finite element analysis techniques enable the modeling to deal with various cycle-times for the moulding process and uncertain dynamics of a die. A combination of off-line training through finite element analysis and training using on-line learning algorithms and experimental data is used for the system identification. Based on the system identification which is experimentally validated using a real system, controllers are designed using fuzzy-logic and self-adaptive PID methods with backpropagation (BP) and radial basis function (RBF) neural networks to tune control parameters. Direct adaptive inverse control and additive feedforward control by adding direct adaptive inverse control to self-adaptive PID controllers are also provided. Through a comparative study, each controller’s performance is verified in terms of response time and tracking accuracy under different moulding processes with multiple cycle-times. Additionally, the improved cooling effectiveness of the conformal cooling channel designed in this study is presented by comparing with a conventional straight channel.

Orientador: Maria Isabel Castreghini de Freitas / Banca: Silvia Selingardi Sampaio / Banca: Cláudia Maria de Almeida / Resumo: Esta pesquisa teve como objetivo analisar o processo de expansão urbano-industrial do município de Americana-SP, com o subsídio de geotecnologias. A ocupação urbana e industrial foi identificada e analisada ao longo de uma série temporal de aproximadamente 60 anos (1940 a 2005), apoiando-se na elaboração e análise do uso da terra do município. Essas etapas permitiram alcançar um diagnóstico da área de estudo atrelada a dados socioeconômicos e a identificação dos vetores de crescimento urbano-industrial para cada década da série temporal. A partir disso, foi desenvolvida a etapa de modelagem dinâmica espacial, utilizando-se um modelo de autômatos celulares para simular os cenários de uso da terra e obter prognósticos para a dinâmica urbana de Americana. Observou-se que a expansão urbano-industrial bem como a formação do contingente populacional do município acompanhou o processo de desenvolvimento do país, sendo o reflexo das políticas governamentais e do desempenho econômico e social que caracterizou cada período. Verificou-se também que o desenvolvimento industrial teve importante papel na ocupação urbana e no crescimento populacional, uma vez que impulsionou os fluxos migratórios que afluíram para o município. A ocupação da quase totalidade do território pela mancha urbana representa um entrave ao crescimento futuro da cidade. Entretanto, mantidas as características de uso e ocupação atuais, a dinâmica territorial deverá ser menor no curto e médio prazo, de acordo com a atual tendência de redução no ritmo de crescimento da população e, por conseqüência da área urbana, semelhante ao observado na maioria dos centros urbanos. Em suma, foram apontadas possíveis aplicações deste trabalho, além de sugestões, sobretudo relacionadas à etapa de modelagem, a qual constitui importante subsídio para o planejamento urbano. / Abstract: The aim of this research is to analyze the urban-industrial expansion process of Americana-SP town by means of geotechnologies. The urban and industrial occupation were identified and analyzed along a temporal series of approximately 60 years (1940 to 2005), based on the elaboration and analysis of land use. These stages allowed to achieve a diagnosis of studied area linked to socioeconomics information and the identification of vectors of urban-industrial growth for each decade of the temporal series. Next, the spatial dynamic modeling using a cellular automata model was developed to simulate land use scenarios and to obtain prognosis for the urban dynamics of Americana. It was observed that the urban-industrial expansion as well as the formation of population contingent followed the process of national development, reflecting governmental politicies and the economic and social performance that characterized each period. Furthermore, the industrial development had an important role on urban occupation and on population growth, since that impelled the rural-urban flows. The spread of urban areas in Americana municipality represents a hindrance to the future city growth. However, if the current land use and occupation trends are maintained the spatial dynamic would be small for the short and medium terms, according to actual tendency of decrease on population growth rates and consequently of urban areas, similar to that observed on the majority of urban centers worldwide. Finally, possible applications this work are pointed out, besides suggestions related to the advances in spatial modeling, since it constitutes an important tool for urban planning. / Mestre

Orientador: Rubens Maciel Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-09T11:12:44Z (GMT). No. of bitstreams: 1 Lima_NadsonMuriloNascimento_M.pdf: 1887705 bytes, checksum: e0761ce0e30dd05a47c9cfbe9b0968ef (MD5) Previous issue date: 2006 / Resumo: A síntese de controladores representa uma importante vertente dos desenvolvimentos atuais no campo da pesquisa acadêmica e industrial. Um controlador bem projetado pode significar sucesso no que se refere aos objetivos de produção, sendo gerados materiais com as especificações desejadas e proporcionando que o sistema opere sob certas restrições, levando em consideração aspectos relativos à operabilidade, segurança e minimização de resíduos. Para tanto, sabe-se que as etapas de modelagem são fundamentais para a delineação de estratégias de controle. No entanto, a obtenção de representações matemáticas precisas e, ao mesmo tempo, aplicáveis para controle da maioria dos processos de interesse da engenharia química é uma tarefa árdua, devido à presença de comportamentos dinâmicos não lineares e variantes ao longo do espaço e do tempo. Deste modo, busca-se a obtenção de modelos mais simples, porém dotados da imprescindível representatividade inerente aos sistemas de produção, a fim de serem projetadas estruturas de controle adequadas para cada necessidade específica. Este trabalho enfoca o desenvolvimento de um controlador híbrido preditivo baseado em modelos nebulosos (fuzzy) tipo Takagi-Sugeno para processos de polimerização, os quais apresentam dinâmicas altamente complexas e de difícil modelagem matemática, dificultando assim a aplicação de metodologias convencionais de controle. Foram considerados dois casos de estudo para análise de desempenho do controlador proposto: o processo de copolimerização em solução do metacrilato de metila e acetato de vinila, e a copolimerização industrial do eteno/1-buteno com catalisador Ziegler-Natta solúvel. Os modelos fenomenológicos de ambos os processos já se encontram descritos na literatura, sendo considerados como plantas virtuais para geração de dados dinâmicos e implementação do controlador. A partir de simulações computacionais, os modelos dinâmicos nebulosos funcionais foram construídos ¿ os quais demonstraram excelentes capacidades para predição das saídas dos processos como uma função dos dados dinâmicos de entrada ¿ sendo, posteriormente, inseridos na estrutura interna do controle preditivo DMC (Dynamic Matrix Control). A escolha do controlador DMC como base para o desenvolvimento da estrutura proposta deve-se ao fato de sua notória aplicabilidade industrial, aliada à simplicidade de projeto e execução, além de possibilitar a incorporação de restrições nas variáveis controladas e manipuladas. Por fim, foram comparados os desempenhos entre os controladores híbrido e DMC convencional para os problemas regulatório e servo, fornecendo resultados satisfatórios em ambas as situações. Isto demonstra o alto potencial do algoritmo proposto para o controle de sistemas não lineares / Abstract: Controller synthesis represents an important slope of recent development in the field of academic and industry research. A well-projected controller may express the success in reference to the aim of production, and it also creates materials with desirable specification and it allows that the system operates under certain restrictions, considering aspects related to operability, safety and minimization of residue. Then, it¿s known that modeling stage is fundamental to delineation of controller strategies. However, the obtaining of precise and applicable mathematical representation to control most of relevant process in chemist engineering is an arduous task, because of the presence of nonlinear dynamic behavior and space-time variation. Therefore, it searches obtaining of simplier models, but gifted of essential representativity inherent to production system, because of this suitable control structure to each specific necessity projected. This work focus on the development of predictive hybrid controller based on fuzzy models, type Takagi-Sugeno, to process of copolymerization, that present high complex dynamic and hard mathematical modeling, what is also difficult to apply conventional methodologies of control. Two study cases that present analyze of purpose controller were considered: the process of copolymerization in solution of methyl methacrylate and vinyl acetate, and industry copolymerization of ethene/1-butene with Ziegler-Natta catalyzation. The phenomenologic models of the two processes have already described in relevant literature, and they are considered as virtual plants to create dynamic data and controller implementation. Based on computer simulation, functional dynamic fuzzy models were made ¿ they demonstrate excellent capacity to output prediction in process as a function of input dynamic data ¿ and they are, subsequently, inserted in an internal structure of DMC (Dynamic Matrix Control) predictive control. The choice of DMC controller as the base to development of proposal structure is responsible to the fact of its well-known industry applicability, allied to simplicity of the project and execution, beyond it makes possible the incorporation of restrictions in controlled and manipulated variables. Finally, the performance between hybrid controller and conventional DMC to regulatory and servo problems were compared, and it supplies satisfactory results in both situation. It demonstrates high potential of propose algorithm to control nonlinear system / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química