A design oriented study for 3R Orthogonal Manipulators With Geometric Simplifications

This paper proposes a method to calculate the largest Regular Dextrous Workspace (RDW) of some types of three-revolute orthogonal manipulators that have at least one of their DH parameters equal to zero. Then a new performance index based on the RDW is introduced, the isocontours of this index are plotted in the parameter space of the interesting types of manipulators and finally an inspection of the domains of the parameter spaces is conducted in order to identify the better manipulator architectures. The RDW is a part of the workspace whose shape is regular (cube, cylinder) and the performances (conditioning index) are bounded inside. The groups of 3R orthogonal manipulators studied have interesting kinematic properties such as, a well-connected workspace that is fully reachable with four inverse kinematic solutions and that does not contain any void. This study is of high interest for the design of alternative manipulator geometries

Workspace and singularity determination of a 7-DoF wrist-partitioned serial manipulator towards graffiti painting

Els robots estan sent utilitzats, cada cop més, en la realització de tasques en la indústria. Molts d'ells també són dissenyats pensats per a realitzar les tasques de la llar. En general, els robots són dissenyats per a facilitar el dia a dia del éssers humans. Però quan es tracta d'obres artístiques, és menys comú trobar-se robots realitzant-les. Nosaltres pretenem sortir de la norma mitjançant l'ús d'un robot per a pintar un grafiti. La motivació per a aconseguir-ho convergeix en la formulació de dues preguntes: "Quin és el volum de treball d'un robot, quan l'orientació del seu efector final està fixada?" i "Donat un pla arbitrari, quina és la major àrea de treball lliure de singularitats en aquest?" Aquesta tesi proposa un mètode per a l'obtenció de les singularitats de posició en un pla qualsevol d'un manipulador serial amb un canell esfèric. El mètode s'ha obtingut mitjançant la combinació d'un mètode de determinació de singularitats de posició, el qual està basat en una tècnica per al decoplat de manipuladors que presenten un canell esfèric, i un algorisme branch-and-prune per a la resolució de sistemes d'equacions. S'ha obtingut el volum de treball d'un manipulador serial de 7 graus de llibertat a través d'un enfocament de cinemàtica directa. Es presenta una metodologia per a obtenir el volum de treball del manipulador serial quan el seu efector final té l'orientació constant i s'aplica per a obtenir aproximacions per al cas de certes orientacions. Es mostra com les singularitats poden ser analitades a través de separar-les en singularitats de posició i d'orientació. el mètode proposat formula i resol les equacions que determinen les singularitats de posició. Pel que fa a les singularitats d'orientació, es mostra que poden ser evitades sense perdre una quantitat significant de volum de treball, des del punt de vista de la posició.Los robots estén siendo utilizados, cada vez más, en la realización de tareas en la industria. Muchos de ellos también son diseñados pensados para realizar las tareas del hogar. En general, los robots son diseñados para facilitar el día a día de los seres humanos. Pero cuando se trata de obras artíticas, es menos común encontrarse a robots realizándolas. Nosotros pretendemos salirnos de lo común mediante el uso de un robot para pintar un grafiti. La motivación por lograrlo converge en la formulación de dos preguntas: "¿Cuál es el volumen de trabajo de un robot, cuando la orientación de su efector final está fijada?" y "Dado un plano arbitrario, ¿cuál es la mayor área de trabajo libre de singularidades en éste?" Esta tesis propone un método para la obtención de las singularidades de posición en un plano cualquiera de un manipulador serial con una muñeca esférica. El método ha sido obtenido mediante la combinación de un método de determinación de singularidades de posición, el cual está basado en una técnica para el decoplado de manipuladores que presentan una muñeca esférica, y un algoritmo branch-and-prune para la resolución de sistemas de ecuaciones. Se ha obtenido el volumen de trabajo de un manipulador serial de 7 grados de libertad a través de un enfoque de cinemática directa. Se presenta la metodología para obtener el volumen de trabajo del manipulador serial cuando su efector final tiene una orientación constante y se aplica para obtener aproximaciones para el caso de ciertas orientaciones. Se muestra cómo las singularidades pueden ser analizadas a través de separarlas en singularidades de posición y de orientación. El método propuesto formula y resuelve las ecuaciones que determinan las singularidades de posición. En cuanto a las singularidades de orientación, se muestra que pueden ser evitadas sin perder una cantidad significante de volumen de trabajo, desde el punto de vista de la posición.Robots are overtaking every day more tasks in the industry. A lot of them are even designed for performing household chores. In general, robots are designed to facilitate the day-to-day of human beings. But when it comes to artistic tasks, it is less usual to see robots performing them. We pretend to stay out of the crowd by using a robot to paint a graffiti. The motivation to achieve this task converges into the statement of two questions: "What is the workspace of a robot, when the orientation of its end-effector is fixed?" and "For a given plane, what is the largest singularity free surface on it?". This thesis proposes a method for the computation of the position singularities of a wrist-partitioned serial manipulator for a given plane. The method is obtained from the combination of a position singularity determination method, which is based on the decoupling technique of a wrist-partitioned manipulator, and a branch-and-prune algorithm for the resolution of systems of equations. The workspace of a 7-DoF serial manipulator is obtained by a forward kinematics approach. A methodology to obtain the constant orientation workspace of a serial manipulator is presented and applied to get approximations for some specific orientations. It is shown how singularities can be analyzed by decoupling them into position singularities and orientation singularities. The proposed method formulates and solves the equation that determines the position singularities. In the case of the orientation singularities, it is shown that they can be avoided without losing a significant amount of the workspace's volume, from the point of view of the position.Outgoin

Hydraulisen puomin voimatakaisinkytketty etäohjaus

Teleoperation has been under study from the mid 1940s, when the first mechanical master-slave manipulators were built to allow safe handling of nuclear material within a hot cell. Since then, need to operate within dangerous, out of reach, uncomfortable, or hazardous environments has then motivated researchers to study teleoperation further. In this thesis, teleoperation of a hydraulic manipulator with electrically driven master manipulator was studied. The workspace of the hydraulic slave manipulator is 5 m in height and it can reach 3 m. The master manipulator has a workspace approximating full arm movement pivoting at the shoulder. Further, the slave manipulator is capable of lifting over 1000 kg, while the master manipulator can lift only 2 kg. Objective of this thesis is to implement virtual decomposition control (VDC) type controller to the master manipulator and create communication channel for the two manipulators. The VDC approach is a subsystem model based feedforward controller. Similar controller for the slave manipulator has been implemented previously. Performance of the developed teleoperation system will be evaluated with experimental implementation measuring the free space motion tracking in two degrees of freedom motion. Results from the experimental implementation indicate accurate motion tracking between the two manipulators. Experimental results indicate less than 15 mm position error between the two manipulators, which considering the size of the HIAB can be considered promising

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

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

Selected topics in robotics for space exploration

Papers and abstracts included represent both formal presentations and experimental demonstrations at the Workshop on Selected Topics in Robotics for Space Exploration which took place at NASA Langley Research Center, 17-18 March 1993. The workshop was cosponsored by the Guidance, Navigation, and Control Technical Committee of the NASA Langley Research Center and the Center for Intelligent Robotic Systems for Space Exploration (CIRSSE) at RPI, Troy, NY. Participation was from industry, government, and other universities with close ties to either Langley Research Center or to CIRSSE. The presentations were very broad in scope with attention given to space assembly, space exploration, flexible structure control, and telerobotics

Biokinematic analysis of human body

Thesis (Doctoral)--Izmir Institute of Technology, Mechanical Engineering, Izmir, 2011Includes bibliographical references (leaves: 118-123)Text in English; Abstract: Turkish and Englishxiii, 123 leavesThis thesis concentrates on the development of rigid body geometries by using method of intersections, where simple geometric shapes representing revolute (R) and prismatic (P) joint motions are intersected by means of desired space or subspace requirements to create specific rigid body geometries in predefined octahedral fixed frame. Using the methodical approach, space and subspace motions are clearly visualized by the help of resulting geometrical entities that have physical constraints with respect to the fixed working volume. Also, this work focuses on one of the main areas of the fundamental mechanism and machine science, which is the structural synthesis of robot manipulators by inserting recurrent screws into the theory. After the transformation unit screw equations are presented, physical representations and kinematic representations of kinematic pairs with recurrent screws are given and the new universal mobility formulations for mechanisms and manipulators are introduced. Moreover the study deals with the synthesis of mechanisms by using quaternion and dual quaternion algebra to derive the objective function. Three different methods as interpolation approximation, least squares approximation and Chebyshev approximation is introduced in the function generation synthesis procedures of spherical four bar mechanism in six precision points. Separate examples are given for each section and the results are tabulated. Comparisons between the methods are also given. As an application part of the thesis, the most important elements of the human body and skeletal system is investigated by means of their kinematic structures and degrees of freedom. At the end of each section, an example is given as a mechanism or manipulator that can represent the behavior of the related element in the human body

Reconfigurable Validation Model for Identifying Kinematic Singularities and Reach Conditions for Articulated Robots and Machine Tools

Automation has led to industrial robots facilitating a wide array of high speed, endurance, and precision operations undertaken in the manufacturing industry today. An acceptable level of functioning and control is therefore vital to the efficacy and successful implementation of such manipulators. This research presents a comprehensive analytical tool for downstream optimization of manipulator design, functionality, and performance. The proposed model is reconfigurable and allows for modelling and validation of different industrial robots. Unique 3D visual models for a manipulator workspace and kinematic singularities are developed to gain an understanding into the task space and reach conditions of the manipulator\u27s end-effector. The developed algorithm also presents a non-conventional and computationally inexpensive solution to the inverse kinematics problem through the use Artificial Neural Networks. Application of the proposed technique is further extended to aid in development of path planning models for a uniform, continuous, and singularity free motion

Path planning for robotic truss assembly

A new Potential Fields approach to the robotic path planning problem is proposed and implemented. Our approach, which is based on one originally proposed by Munger, computes an incremental joint vector based upon attraction to a goal and repulsion from obstacles. By repetitively adding and computing these 'steps', it is hoped (but not guaranteed) that the robot will reach its goal. An attractive force exerted by the goal is found by solving for the the minimum norm solution to the linear Jacobian equation. A repulsive force between obstacles and the robot's links is used to avoid collisions. Its magnitude is inversely proportional to the distance. Together, these forces make the goal the global minimum potential point, but local minima can stop the robot from ever reaching that point. Our approach improves on a basic, potential field paradigm developed by Munger by using an active, adaptive field - what we will call a 'flexible' potential field. Active fields are stronger when objects move towards one another and weaker when they move apart. An adaptive field's strength is individually tailored to be just strong enough to avoid any collision. In addition to the local planner, a global planning algorithm helps the planner to avoid local field minima by providing subgoals. These subgoals are based on the obstacles which caused the local planner to fail. A best-first search algorithm A* is used for graph search

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