Two-mode overconstrained three-DOFs rotational-translational linear-motor-based parallel-kinematics mechanism for machine tool applications

The paper introduces a family of three-DOFs translational-rotational Parallel-Kinematics Mechanisms (PKMs) as well as the mobility analysis of such family using Lie-group theory. Each member of this family has two-rotational one-translational DOFs. A novel mechanism is presented and analyzed as a representative of that family. The use and the practical value of that modular mechanism are emphasized.<br /

Position and singularity analysis of a class of planar parallel manipulators with a reconfigurable end-effector

Parallel robots with configurable platforms are a class of robots in which the end-effector has an inner mobility, so that its overall shape can be reconfigured: in most cases, the end-effector is thus a closed-loop kinematic chain composed of rigid links. These robots have a greater flexibility in their motion and control with respect to rigid-platform parallel architectures, but their kinematics is more challenging to analyze. In our work, we consider n-RRR planar configurable robots, in which the end-effector is a chain composed of n links and revolute joints, and is controlled by n rotary actuators located on the base of the mechanism. In particular, we study the geometrical design of such robots and their direct and inverse kinematics for n = 4, n = 5 and n = 6; we employ the bilateration method, which can simplify the kinematic analysis and allows us to generalize the approach and the results obtained for the 3-RRR mechanism to n-RRR robots (with n &gt; 3). Then, we study the singularity configurations of these robot architectures. Finally, we present the results from experimental tests that have been performed on a 5–RRR robot prototype

Contribuições para o projeto de manipuladores paralelos através da síntese do tipo

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Mecânica, Florianópolis, 2011A Síntese do Tipo é uma fase fundamental para o projeto de manipuladores paralelos. Esse processo de síntese consiste em uma abordagem sistemática, na qual um método é utilizado para gerar todas as possíveis estruturas mecânicas que sejam capazes de realizar um tipo de movimento. A Síntese do Tipo apresenta duas etapas principais: (1) Geração de pernas e (2) Montagem de manipuladores paralelos. A geração de pernas consiste em gerar cadeias cinemáticas que possuam tipos de movimentos de saída específicos. Essas cadeias cinemáticas são compostas por elos e juntas que apresentam configurações geométricas determinadas. Para a montagem dos manipuladores paralelos, as pernas geradas na primeira etapa são utilizadas. O movimento de saída que cada manipulador apresentará, ao final de sua montagem, dependerá do tipo de perna utilizado e do posicionamento de fixação das pernas. Neste trabalho será apresentada uma revisão dos principais métodos de síntese do tipo existentes, e as soluções de pernas geradas por cada método serão classificadas e organizadas utilizando uma única notação. Será apresentado também um novo método de síntese do tipo para a fase de geração de pernas. O algoritmo implementado para esse novo método combina características de algoritmos genéticos e teoria de helicoides. As soluções geradas pelo algoritmo foram comparadas com os resultados encontrados na literatura e, com isso, o método proposto foi validado

Advances in Robot Kinematics : Proceedings of the 15th international conference on Advances in Robot Kinematics

International audienceThe motion of mechanisms, kinematics, is one of the most fundamental aspect of robot design, analysis and control but is also relevant to other scientific domains such as biome- chanics, molecular biology, . . . . The series of books on Advances in Robot Kinematics (ARK) report the latest achievement in this field. ARK has a long history as the first book was published in 1991 and since then new issues have been published every 2 years. Each book is the follow-up of a single-track symposium in which the participants exchange their results and opinions in a meeting that bring together the best of world’s researchers and scientists together with young students. Since 1992 the ARK symposia have come under the patronage of the International Federation for the Promotion of Machine Science-IFToMM.This book is the 13th in the series and is the result of peer-review process intended to select the newest and most original achievements in this field. For the first time the articles of this symposium will be published in a green open-access archive to favor free dissemination of the results. However the book will also be o↵ered as a on-demand printed book.The papers proposed in this book show that robot kinematics is an exciting domain with an immense number of research challenges that go well beyond the field of robotics.The last symposium related with this book was organized by the French National Re- search Institute in Computer Science and Control Theory (INRIA) in Grasse, France