Contribuições para a enumeração e para a análise de mecanismos e manipuladores paralelos

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Mecânica, Florianópolis, 2010A fase de projeto conceitual demecanismos emanipuladores paralelos, i.e. estruturas cinematicas, destina-se ao desenvolvimento da concepçao da cadeia cinematica. As etapas fundamentais para o desenvolvimento da concepao da cadeia cinematica sao sintese e analise. A sintese corresponde à enumeraçao de concepcoes e a analise corresponde `a seleçao das concepçoes mais promissoras considerando os requisitos de projeto. O objetivo deste trabalho é aplicar ferramentas da teoria de grupos e teoria de grafos para a enumeraçao e para a analise de estruturas cinematicas. A enumeraçao sera desenvolvida de forma sistematica em tres niveis: enumeraçao de cadeias cinematicas, enumeraçao de mecanismos e enumeraçao de manipuladores paralelos. A aplicaçao de ferramentas da teoria de grafos e grupos permite desenvolver novos metodos para enumeraçao e, consequentemente, obter novos resultados. A analise sera simplificada considerando um novo metodo que avalia as simetrias das cadeias cinematicas. Uma cadeia cinematica é representada de forma univoca atraves de um grafo. A representaçao atraves do grafo permite a manipulaçao computacional do problema de enumeraçao de cadeias cinematicas. A aplicaçao de ferramentas integradas da teoria de grafos e teoria de grupos permite identificar as simetrias das cadeias cinematicas atraves do grupo de automorfismos do grafo e, assim, é possivel identificar quais são as possiveis escolhas de base para novos mecanismos e avaliar quais sao as possiveis escolhas de base e efetuador final para manipuladores paralelos. O primeiro nivel da sintese corresponde à enumeraçao de cadeias cinematicas com determinada mobilidade, numero de elos, numero de juntas que operam num determinado sistema de helicoides. O segundo nivel da sintese corresponde a enumeraçao de mecanismos. Um mecanismo é uma cadeia cinematica com um elo escolhido para ser a base. Assim, a enumeraçao de mecanismos consiste em determinar todas as possiveis escolhas de bases para uma determinada cadeia cinematica. O principal conceito empregado neste nivel é o de simetria de grafos não coloridos e orbitas do grupo de automorfismos. O terceiro nivel da sintese corresponde `a enumeraçao de manipuladores paralelos. Um manipulador paralelo é uma cadeia cinematica com um elo escolhido para ser a base e outro para ser o efetuador final. Em outras palavras, um manipulador paralelo é um mecanismo com um elo escolhido para ser o efetuador final. Assim, a enumeraçao de manipuladores paralelos consiste em determinar todas as possiveis escolhas de efetuador final para um determinado mecanismo. O principal conceito empregado neste nivel é a simetria de grafos coloridos e orbitas do grupo de automorfismos de grafos coloridos. Na etapa de analise das concepcoes enumeradas serao abordadas propriedades bem estabelecidas na literatura: mobilidade, variedade, conectividade, grau de controle, redundancia e simetria. Mobilidade e variedade sao propriedades globais das estruturas cinematicas. Conectividade, grau de controle e redundancia sao propriedades locais, i.e. entre dois elos da estrutura cinematica e sao dadas por matrizes n×n, onde n é o número de elos da cadeia. A simetria pode ser considerada uma propriedade global e/ou local da estrutura cinem´atica. A aplicaçao de ferramentas integradas da teoria de grafos e teoria de grupos permite demonstrar que as propriedades locais sao invariantes pela acao do grupo de automorfismos do grafo, i.e. elas sao propriedades simetricas. Desta forma, a representaçao matricial é reduzida de n×n para o×n, onde o é o numero de orbitas do grupo de automorfismos do grafo aassociado à estrutura cinematica. Essa abordagem permite simplificar a analise de estruturas cinematicas apenas considerando as simetrias das cadeia associadas

Parallel Manipulators

In recent years, parallel kinematics mechanisms have attracted a lot of attention from the academic and industrial communities due to potential applications not only as robot manipulators but also as machine tools. Generally, the criteria used to compare the performance of traditional serial robots and parallel robots are the workspace, the ratio between the payload and the robot mass, accuracy, and dynamic behaviour. In addition to the reduced coupling effect between joints, parallel robots bring the benefits of much higher payload-robot mass ratios, superior accuracy and greater stiffness; qualities which lead to better dynamic performance. The main drawback with parallel robots is the relatively small workspace. A great deal of research on parallel robots has been carried out worldwide, and a large number of parallel mechanism systems have been built for various applications, such as remote handling, machine tools, medical robots, simulators, micro-robots, and humanoid robots. This book opens a window to exceptional research and development work on parallel mechanisms contributed by authors from around the world. Through this window the reader can get a good view of current parallel robot research and applications

Industrial Robotics

This book covers a wide range of topics relating to advanced industrial robotics, sensors and automation technologies. Although being highly technical and complex in nature, the papers presented in this book represent some of the latest cutting edge technologies and advancements in industrial robotics technology. This book covers topics such as networking, properties of manipulators, forward and inverse robot arm kinematics, motion path-planning, machine vision and many other practical topics too numerous to list here. The authors and editor of this book wish to inspire people, especially young ones, to get involved with robotic and mechatronic engineering technology and to develop new and exciting practical applications, perhaps using the ideas and concepts presented herein

The research of five-bar robot for pressurized autosampling for enhanced oil recovery research

Robots have been widely used in industry and are becoming popular in people’s daily lives. It makes production more efficient and everyday life more convenient. In this research, a robotic auto-sampler is designed, developed and tested to sample and collect two-phase fluids from a core flooding. First of all, this thesis introduces the history of parallel robot industry the state of the art. Then, based on the problem statement, the most reasonable concept is chosen as the Five-Bar parallel robot. Theoretical simulations are made including kinematic analysis to calculate its mechanical dimension and dynamic analysis to calculate the actuator torque. As a result of that, the theoretical dimensions can be obtained and actuators can be chosen. In the design and control phase, the entire integrated system is presented in detail. This thesis researches the design process of an auto-sampler based on a five-bar robot. From the proposed problem to the robot fabrication and programming, the entire system is designed, analyzed, built and tested

Autonomous Navigation of Automated Guided Vehicle Using Monocular Camera

This paper presents a hybrid control algorithm for Automated Guided Vehicle (AGV) consisting of two independent control loops: Position Based Control (PBC) for global navigation within manufacturing environment and Image Based Visual Servoing (IBVS) for fine motions needed for accurate steering towards loading/unloading point. The proposed hybrid control separates the initial transportation task into global navigation towards the goal point, and fine motion from the goal point to the loading/unloading point. In this manner, the need for artificial landmarks or accurate map of the environment is bypassed. Initial experimental results show the usefulness of the proposed approach.COBISS.SR-ID 27383808

Autonomous Navigation of Automated Guided Vehicle Using Monocular Camera

This paper presents a hybrid control algorithm for Automated Guided Vehicle (AGV) consisting of two independent control loops: Position Based Control (PBC) for global navigation within manufacturing environment and Image Based Visual Servoing (IBVS) for fine motions needed for accurate steering towards loading/unloading point. The proposed hybrid control separates the initial transportation task into global navigation towards the goal point, and fine motion from the goal point to the loading/unloading point. In this manner, the need for artificial landmarks or accurate map of the environment is bypassed. Initial experimental results show the usefulness of the proposed approach.COBISS.SR-ID 27383808

Optimization of Operation Sequencing in CAPP Using Hybrid Genetic Algorithm and Simulated Annealing Approach

In any CAPP system, one of the most important process planning functions is selection of the operations and corresponding machines in order to generate the optimal operation sequence. In this paper, the hybrid GA-SA algorithm is used to solve this combinatorial optimization NP (Non-deterministic Polynomial) problem. The network representation is adopted to describe operation and sequencing flexibility in process planning and the mathematical model for process planning is described with the objective of minimizing the production time. Experimental results show effectiveness of the hybrid algorithm that, in comparison with the GA and SA standalone algorithms, gives optimal operation sequence with lesser computational time and lesser number of iterations

Optimization of Operation Sequencing in CAPP Using Hybrid Genetic Algorithm and Simulated Annealing Approach

In any CAPP system, one of the most important process planning functions is selection of the operations and corresponding machines in order to generate the optimal operation sequence. In this paper, the hybrid GA-SA algorithm is used to solve this combinatorial optimization NP (Non-deterministic Polynomial) problem. The network representation is adopted to describe operation and sequencing flexibility in process planning and the mathematical model for process planning is described with the objective of minimizing the production time. Experimental results show effectiveness of the hybrid algorithm that, in comparison with the GA and SA standalone algorithms, gives optimal operation sequence with lesser computational time and lesser number of iterations

Robotics 2010

Without a doubt, robotics has made an incredible progress over the last decades. The vision of developing, designing and creating technical systems that help humans to achieve hard and complex tasks, has intelligently led to an incredible variety of solutions. There are barely technical fields that could exhibit more interdisciplinary interconnections like robotics. This fact is generated by highly complex challenges imposed by robotic systems, especially the requirement on intelligent and autonomous operation. This book tries to give an insight into the evolutionary process that takes place in robotics. It provides articles covering a wide range of this exciting area. The progress of technical challenges and concepts may illuminate the relationship between developments that seem to be completely different at first sight. The robotics remains an exciting scientific and engineering field. The community looks optimistically ahead and also looks forward for the future challenges and new development