Mathematical principles for the design of isostatic mount systems for dynamic structures

Isostatic mounts are used in applications like telescopes and robotics to move and hold part of a structure in a desired pose relative to the rest, by driving some controls rather than driving the subsystem directly. To achieve this successfully requires an understanding of the structure of the coupled space of configurations and controls, and of the singularities of the mapping from the coupled space to the space of controls. It is crucial to avoid such singularities because generically they lead to large constraint forces and internal stresses which can cause distortion. In this paper we outline design principles for isostatic mount systems for dynamic structures, with particular emphasis on robots

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

Advanced Strategies for Robot Manipulators

Amongst the robotic systems, robot manipulators have proven themselves to be of increasing importance and are widely adopted to substitute for human in repetitive and/or hazardous tasks. Modern manipulators are designed complicatedly and need to do more precise, crucial and critical tasks. So, the simple traditional control methods cannot be efficient, and advanced control strategies with considering special constraints are needed to establish. In spite of the fact that groundbreaking researches have been carried out in this realm until now, there are still many novel aspects which have to be explored

Singularity-free workspace analysis and geometric optimization of parallel mechanisms

Les mécanismes parallèles sont fréquemment utilisés comme robots manipulateurs, comme simulateurs de mouvement, comme machines parallèles, etc. Cependant, à cause des chaînes cinématiques fermées qui caractérisent leur architecture, le mouvement de leur plateforme est limité et des singularités cinématiques complexes peuvent apparaître à l'intérieur de leur espace de travail. Par conséquent, une maximisation l'espace de travail libre de singularité pour ce type de mécanismes est souhaitable dans un contexte de conception. Dans cette thèse, deux types de mécanismes parallèles sont étudiés: les mécanismes parallèles plans ?avec, en particulier le 3-RPR? et les mécanismes spatiaux ?avec, en particulier, la plateforme de Gough-Stewart. Pour chaque type de mécanisme parallèle, une forme simple d'équation de singularité est obtenue. Le principe consiste à séparer l'origine O' du repère mobile du point considéré P et de faire coïncider O' avec un point particulier de la plateforme. L'équation ainsi obtenue est l'équation de singularité du point P de la plateforme qui contient un ensemble minimal de paramètres géométriques. Par ailleurs, il est prouvé que les centres des cercles et sphères définissant l'espace de travail se trouvent exactement sur les lieux de singularité. Cette observation et l'équation de singularité simplifiée constituent les points de départ de l'analyse de l'espace de travail libre de singularité ainsi que de l'optimisation géométrique. Pour le mécanisme parallèle plan 3-RPR, l'espace de travail libre de singularité et les limites correspondantes pour la longueur des pattes dans une orientation prescrite sont déterminés. Ensuite l'architecture optimale qui permet d'obtenir un espace de travail maximal tout en étant libre de singularité est discutée. En ce qui concerne la plateforme de Gough-Stewart, cette thèse se concentre sur le manipulateur symétrique simplifié minimal (MSSM). Comme une plateforme de Gough- Stewart a 6 degrés de liberté, son espace de travail se divise en deux: l'espace de travail en position (ou simplement espace de travail) et l'espace de travail en orientation. A partir de l'équation de singularité simplifiée, une procédure générale est développée afin de déterminer l'espace de travail libre de singularité maximal autour d'un point particulier dans une orientation donnée, et afin de déterminer les limites correspondantes des longueurs de patte. Dans le but de maximiser l'espace de travail libre de singularité en orientation, un algorithme est présenté qui optimise les trois angles d'orientation. Sachant qu'une plateforme fonctionne habituellement pour une certaine gamme d'orientations, deux algorithmes qui calculent l'espace de travail en orientation libre de singularité maximal sont présentés. En utilisant les angles d'Euler en roulis, tangage et lacet, l'espace de travail en orientation pour une position prescrite peut être défini par 12 surfaces. Basé sur ce fait, un algorithme numérique est présenté qui évalue et représente l'espace de travail en orientation pour une position prescrite dans les limites données de longueur de patte. Ensuite, une procédure est proposée afin de déterminer l'espace de travail en orientation libre singularité maximal ainsi que les limites correspondantes des longueurs de patte. En pratique, une plateforme peut fonctionner dans un ensemble de positions. Ainsi, l'effet de la position de travail sur l'espace de travail en orientation libre de singularité maximal est analysé et deux algorithmes sont proposés pour calculer ce dernier pour tout un ensemble de positions particulières. Finalement, un algorithme qui optimise les paramètres géométriques est développé dans le but de déterminer l'architecture optimale qui permet à la plateforme de MSSM Gough-Stewart d'obtenir l'espace de travail libre singularité maximal autour d'une position particulière pour l'orientation de référence. Les résultats obtenus peuvent être utilisés pour la conception géométrique, la configuration des paramètres (longueur des pattes) ou la planification de trajectoires libres de singularité des mécanismes parallèles considérés. En outre, les algorithmes proposés peuvent également être appliqués à d'autres types de mécanismes parallèles

Kinematics and Robot Design II (KaRD2019) and III (KaRD2020)

This volume collects papers published in two Special Issues “Kinematics and Robot Design II, KaRD2019” (https://www.mdpi.com/journal/robotics/special_issues/KRD2019) and “Kinematics and Robot Design III, KaRD2020” (https://www.mdpi.com/journal/robotics/special_issues/KaRD2020), which are the second and third issues of the KaRD Special Issue series hosted by the open access journal robotics.The KaRD series is an open environment where researchers present their works and discuss all topics focused on the many aspects that involve kinematics in the design of robotic/automatic systems. It aims at being an established reference for researchers in the field as other serial international conferences/publications are. Even though the KaRD series publishes one Special Issue per year, all the received papers are peer-reviewed as soon as they are submitted and, if accepted, they are immediately published in MDPI Robotics. Kinematics is so intimately related to the design of robotic/automatic systems that the admitted topics of the KaRD series practically cover all the subjects normally present in well-established international conferences on “mechanisms and robotics”.KaRD2019 together with KaRD2020 received 22 papers and, after the peer-review process, accepted only 17 papers. The accepted papers cover problems related to theoretical/computational kinematics, to biomedical engineering and to other design/applicative aspects

On the Statics, Dynamics, and Stability of Continuum Robots: Model Formulations and Efficient Computational Schemes

This dissertation presents advances in continuum-robotic mathematical-modeling techniques. Specifically, problems of statics, dynamics, and stability are studied for robots with slender elastic links. The general procedure within each topic is to develop a continuous theory describing robot behavior, develop a discretization strategy to enable simulation and control, and to validate simulation predictions against experimental results.Chapter 1 introduces the basic concept of continuum robotics and reviews progress in the field. It also introduces the mathematical modeling used to describe continuum robots and explains some notation used throughout the dissertation.The derivation of Cosserat rod statics, the coupling of rods to form a parallel continuum robot (PCR), and solution of the kinematics problem are reviewed in Chapter 2. With this foundation, soft real-time teleoperation of a PCR is demonstrated and a miniature prototype robot with a grasper is controlled.Chapter 3 reviews the derivation of Cosserat rod dynamics and presents a discretization strategy having several desirable features, such as generality, accuracy, and potential for good computational efficiency. The discretized rod model is validated experimentally using high speed camera footage of a cantilevered rod. The discretization strategy is then applied to simulate continuum robot dynamics for several classes of robot, including PCRs, tendon-driven robots, fluidic actuators, and concentric tube robots.In Chapter 4, the stability of a PCR is analyzed using optimal control theory. Conditions of stability are gradually developed starting from a single planar rod and finally arriving at a stability test for parallel continuum robots. The approach is experimentally validated using a camera tracking system.Chapter 5 provides closing discussion and proposes potential future work

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

Robot Manipulators

Robot manipulators are developing more in the direction of industrial robots than of human workers. Recently, the applications of robot manipulators are spreading their focus, for example Da Vinci as a medical robot, ASIMO as a humanoid robot and so on. There are many research topics within the field of robot manipulators, e.g. motion planning, cooperation with a human, and fusion with external sensors like vision, haptic and force, etc. Moreover, these include both technical problems in the industry and theoretical problems in the academic fields. This book is a collection of papers presenting the latest research issues from around the world

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

Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015

This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version