58 research outputs found
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
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
Modular and Analytical Methods for Solving Kinematics and Dynamics of Series-Parallel Hybrid Robots
While serial robots are known for their versatility in applications, larger workspace, simpler modeling and control, they have certain disadvantages like limited precision, lower stiffness and poor dynamic characteristics in general. A parallel robot can offer higher stiffness, speed, accuracy and payload capacity, at the downside of a reduced workspace and a more complex geometry that needs careful analysis and control. To bring the best of the two worlds, parallel submechanism modules can be connected in series to achieve a series-parallel hybrid robot with better dynamic characteristics and larger workspace. Such a design philosophy is being used in several robots not only at DFKI (for e.g., Mantis, Charlie, Recupera Exoskeleton, RH5 humanoid etc.) but also around the world, for e.g. Lola (TUM), Valkyrie (NASA), THOR (Virginia Tech.) etc.These robots inherit the complexity of both serial and parallel architectures. Hence, solving their kinematics and dynamics is challenging because they are subjected to additional geometric loop closure constraints. Most approaches in multi-body dynamics adopt numerical resolution of these constraints for the sake of generality but may suffer from inaccuracy and performance issues. They also do not exploit the modularity in robot design. Further, closed loop systems can have variable mobility, different assembly modes and can impose redundant constraints on the equations of motion which deteriorates the quality of many multi-body dynamics solvers. Very often only a local view to the system behavior is possible. Hence, it is interesting for geometers or kinematics researchers, to study the analytical solutions to geometric problems associated with a specific type of parallel mechanism and their importance over numerical solutions is irrefutable. Techniques such as screw theory, computational algebraic geometry, elimination and continuation methods are popular in this domain. But this domain specific knowledge is often underrepresented in the design of model based kinematics and dynamics software frameworks. The contributions of this thesis are two-fold. Firstly, a rigorous and comprehensive kinematic analysis is performed for the novel parallel mechanisms invented recently at DFKI-RIC such as RH5 ankle mechanism and Active Ankle using approaches from computational algebraic geometry and screw theory. Secondly, the general idea of a modular software framework called Hybrid Robot Dynamics (HyRoDyn) is presented which can be used to solve the geometry, kinematics and dynamics of series-parallel hybrid robotic systems with the help of a software database which stores the analytical solutions for parallel submechanism modules in a configurable and unit testable manner. HyRoDyn approach is suitable for both high fidelity simulations and real-time control of complex series-parallel hybrid robots. The results from this thesis has been applied to two robotic systems namely Recupera-Reha exoskeleton and RH5 humanoid. The aim of this software tool is to assist both designers and control engineers in developing complex robotic systems of the future. Efficient kinematic and dynamic modeling can lead to more compliant behavior, better whole body control, walking and manipulating capabilities etc. which are highly desired in the present day and future robotic applications
MUSME 2011 4 th International Symposium on Multibody Systems and Mechatronics
El libro de actas recoge las aportaciones de los autores a través de los correspondientes artículos a la Dinámica de Sistemas Multicuerpo y la Mecatrónica (Musme). Estas disciplinas se han convertido en una importante herramienta para diseñar máquinas, analizar prototipos virtuales y realizar análisis CAD sobre complejos sistemas mecánicos articulados multicuerpo. La dinámica de sistemas multicuerpo comprende un gran número de aspectos que incluyen la mecánica, dinámica estructural, matemáticas aplicadas, métodos de control, ciencia de los ordenadores y mecatrónica. Los artículos recogidos en el libro de actas están relacionados con alguno de los siguientes tópicos del congreso:
Análisis y síntesis de mecanismos
; Diseño de algoritmos para sistemas mecatrónicos
; Procedimientos de simulación y resultados
; Prototipos y rendimiento
; Robots y micromáquinas
; Validaciones experimentales
; Teoría de simulación mecatrónica
; Sistemas mecatrónicos
; Control de sistemas mecatrónicosUniversitat Politècnica de València (2011). MUSME 2011 4 th International Symposium on Multibody Systems and Mechatronics. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/13224Archivo delegad
Robotic implantation of intracerebral electrodes for deep brain stimulation
Dissertação de mestrado integrado em Engenharia BiomédicaThe objective of this dissertation is to develop an initial approach of a robotic
system to play an assistive role in Deep Brain Stimulation (DBS) stereotactic
neurosurgery. The robot is expected to position and manipulate several surgical
instrumentation in a passive or semi-active role according to pre-operative
directives and to medical team instructions. The current impact of neurological
disorders sensitive to DBS, the underlying knowledge of neurostimulation and neuroanatomy,
and practical insight about DBS surgery is studied to understand the
ultimate goal of our project. We elaborated a state of the art search on neurosurgery
robots to get the picture of what was done and what could be improved.
Upon determining the optimal robotic system characteristics for DBS surgery, we
conducted a search on industrial robotic manipulators to select the best candidates.
The geometric and differential kinematic equations are developed for each
robotic manipulator. To test the kinematic equations and the control application
in a virtual operating room environment, we used the CoopDynSim simulator. Being
this simulator oriented to mobile robots, we introduced the serial manipulator
concept and implemented the selected robots with all specifications. We designed a
control application to manoeuvre the robot and devised an initial interface towards
positioning/manipulation of instrumentation along surgical trajectories, while emphasizing
safety procedures. Although it was impossible to assess the robot’s
precision in simulation, we studied how and where to place the manipulator to
avoid collisions with surrounding equipment without restricting its flexibility.O objectivo desta dissertação é o desenvolvimento de uma abordagem inicial a
um sistema robótico para desempenhar um papel de assistência em neurocirurgia
estereotáxica de Estimulação Cerebral Profunda (DBS). O robô deve posicionar e
manipular variados instrumentos cirúrgicos de uma forma passiva ou semi-ativa de
acordo com diretivas pré-operativas ou com as instruções da equipa médica. O impacto
atual dos distúrbios neurológicos sensíveis a DBS, o conhecimento subjacente
de neuro-estimulação e neuro-anatomia, e conhecimento prático sobre a cirurgia de
DBS são estudados para concluir sobre o objectivo final do nosso projeto. Nós elaborámos
uma pesquisa sobre o estado da arte em robots neurocirúrgicos para perceber
o que tem sido feito e o que pode ser melhorado. Após determinar o conjunto
óptimo de características de um sistema robótico para cirurgia de DBS, nós procuramos
manipuladores robóticos industriais para escolher os melhores candidatos.
As cinemáticas geométricas e diferenciais são desenvolvidas para cada manipulador
robótico. Para testar as equações cinemáticas e a aplicação de controlo num
ambiente virtual de uma sala de operações, nós usamos o simulador CoopDynSim.
Sendo este manipulador orientado a robôs móveis, nós introduzimos o conceito
de manipuladores em série e implementamos os robôs selecionados com todas as
especificações. Nós projetamos uma aplicação de controlo para manobrar os robôs
e desenvolvemos uma interface inicial no sentido do posicionamento/manipulação
de instrumentação ao longo de trajetórias cirúrgicas, enfatizando os procedimentos
de segurança. Embora não tenha sido possível avaliar a precisão do robô em
simulação, nós estudamos como e onde posicionar o manipulador de forma a evitar
colisões com o equipamento circundante sem restringir a sua flexibilidade
Development of a Robotic Positioning and Tracking System for a Research Laboratory
Measurement of residual stress using neutron or synchrotron diffraction relies on the accurate alignment of the sample in relation to the gauge volume of the instrument. Automatic sample alignment can be achieved using kinematic models of the positioning system provided the relevant kinematic parameters are known, or can be determined, to a suitable accuracy.
The main problem addressed in this thesis is improving the repeatability and accuracy of the sample positioning for the strain scanning, through the use of techniques from robotic calibration theory to generate kinematic models of both off-the-shelf and custom-built positioning systems. The approach is illustrated using a positioning system in use on the ENGIN-X instrument at the UK’s ISIS pulsed neutron source comprising a traditional XYZΩ table augmented with a triple axis manipulator. Accuracies better than 100microns were achieved for this compound system. Although discussed here in terms of sample positioning systems these methods are entirely applicable to other moving instrument components such as beam shaping jaws and detectors.
Several factors could lead to inaccurate positioning on a neutron or synchrotron diffractometer. It is therefore essential to validate the accuracy of positioning especially during experiments which require a high level of accuracy. In this thesis, a stereo camera system is developed to monitor the sample and other moving parts of the diffractometer. The camera metrology system is designed to measure the positions of retroreflective markers attached to any object that is being monitored. A fully automated camera calibration procedure is developed with an emphasis on accuracy. The potential accuracy of this system is demonstrated and problems that limit accuracy are discussed. It is anticipated that the camera system would be used to correct the positioning system when the error is minimal or notify the user of the error when it is significant
Type synthesis and static balancing of a class of deployable mechanisms
This thesis addresses the type synthesis and static balancing of a class of deployable
mechanisms, which can be applied in applications in many areas including aerospace and
daily life.
Novel construction methods are proposed to obtain the deployable mechanisms. First,
the type synthesis of the foldable 8-revolute joint (R) linkages with multiple modes is
presented. Two types of linkages are constructed by connecting planar 4R linkages and
spherical 4R linkages. The obtained linkages can be folded into two layers or four layers,
and have multiple motion modes. A spatial triad is also adopted to build single-loop
linkages, then the single-loop linkages are connected using spherical (S) joints or RRR
chains to obtain deployable polyhedral mechanisms (DPMs). The DPMs have only 1-
degree-of-freedom (DOF) when deployed, and several mechanisms with 8R linkages and
10R linkages have multiple motion modes and can switch modes through transition
positions. In addition, when connecting single-loop linkages using half the number of the
RRR chains, the prism mechanisms obtain an additional 1-DOF rotation mode.
Furthermore, the DPMs are developed into statically balanced mechanisms. The
geometric static balancing approaches for the planar 4R parallelogram linkages, planar
manipulators, spherical manipulators and spatial manipulators are developed so that the
mechanisms can counter gravity while maintaining the positions of the mechanisms. Only
springs are used to design the statically balanced system readily, with almost no
calculation. A novel numerical optimization approach is also introduced which adopts the
sum of squared differences of the potential energies as the objective function. Using the
proposed static balancing approaches, the 8R linkages and the DPMs presented in this
thesis can be statically balanced
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