Kinematic Design and Description of Industrial Robotic Chains

Generally speaking, the problem of synthesis of mechanism can be broken down into three sub problems: i) the specification of the problem, ii) the topological synthesis of the mechanism and iii) the dimensional synthesis. This chapter relates in particular to the second sub problem. The chapter could be useful for teachers, researchers, engineers and students who are confronted with the various types of problems concerning the choice of kinematic chains in the initial phase of the topological structural design of an industrial robot. The principal goal of the chapter is to present an overview concerning the chronology of the design of the kinematic chain of an industrial robot. It starts with a review of the methods of synthesis of mechanisms provided by the MMT; then it deals with their representation, validation and concludes with the application of these mechanisms in the initial design phase of industrial robots. The chapter begins with the presentation of a new method for structural synthesis of planar link chains in robotics. It is based on the notion of logical equations. After a brief reminder of the theory of Modular Structural Groups (MSG), and of the connectivity and mobility laws of MMT, various levels of abstraction are studied concerning the complexity of the structure. This permits the synthesis of planar chains with various degrees of complexity expressed by the number of links, joints and the degree of mobility. The logical equations allow the association of MSGs of type A and closed chains of type G. The rules for associations of groups are also presented. The aim is to execute all the possible combinations to join or transform the links in order to obtain as many structures as possible by avoiding those, which are isomorphic. The association of two groups allows the elaboration of different closed chains of upper level. However there are some defect structures, which do not respect the connectivity and mobility laws. Therefore great care has been taken to avoid them. The problem of degenerated structures is central in the synthesis of structures. It concerns especially chains with two and more degrees of mobility. The problem of defect, degeneration and isomorphism is then approached. Finally, a method for description of chains by contours and molecules is proposed. It enables the reduction of the number of the topological structures of the robots concerning the position of the frame and the end-effector of the robot by comparing their respective molecules. This method is then applied for the description of the structures thus obtained (logical equations approach) and for the description of the topology of the principal structure of the industrial robots in the initial phase of their design

Estrategia de optimización para la síntesis dimensional de un robot paralelo 5R para una aplicación de mesa de corte

Planar robots can perform industrial tasks such as CNC X-Y cutter. Among them, the 5R two-degrees-of-freedom (2-DoF) planar parallel robot can become a useful conceptual design. Parallel robots are made of several closed kinematic chains, which gives them a structure enabling to bear more payload. These robots present the advantages of better load/size capacity, speed, rigidity and precision, while their main drawback is the limited workspace. The paper aim to design the 5R-2DoF parallel robot so that its reachable workspace will be maximum and also with optimal dexterity. In this sense, we take advantage of the Genetic Algorithms (GA) in order to develop an approach for optimal design of the robot. The paper shows a path to follow to design the robot taking into account a maximum workspace with dexterity. We present two study cases to test the performance of the proposed approach.Los robot planos pueden realizar tareas industriales como el corte X-Y. En este sentido, el robot paralelo plano de 2 Grados de Libertad (GdL) y 5 pares de revoluta (R) puede ser empleado como concepto de diseño. Un robot paralelo está conformado por varias cadenas cinemáticas cerradas, lo que le da una estructura que permite una mejor distribución de las cargas soportadas. Los robots paralelos presumen características ventajosas en cuanto a la relación peso del robot y peso de la carga soportada,  tienen mayor velocidad, rigidez y precisión. Como principal contrapartida, los robots paralelos tienen un espacio de trabajo reducido. En este trabajo, se busca diseñar un robot plano de 2GdL 5R de forma tal que su espacio de trabajo sea el máximo posible y que además presente óptima destreza. Para ello, se toma ventaja de la  técnica de optimización Algoritmos Genéticos (AG) y se desarrolla un procedimiento numérico para optimizar el espacio de trabajo y la agilidad con que el robot puede moverse (destreza). Dos casos de estudio ejemplifican la implementación del procedimiento propuesto

Estrategia de optimización para la síntesis dimensional de un robot paralelo 5R para una aplicación de mesa de corte

Planar robots can perform industrial tasks such as CNC X-Y cutter. Among them, the 5R two-degrees-of-freedom (2-DoF) planar parallel robot can become a useful conceptual design. Parallel robots are made of several closed kinematic chains, which gives them a structure enabling to bear more payload. These robots present the advantages of better load/size capacity, speed, rigidity and precision, while their main drawback is the limited workspace. The paper aim to design the 5R-2DoF parallel robot so that its reachable workspace will be maximum and also with optimal dexterity. In this sense, we take advantage of the Genetic Algorithms (GA) in order to develop an approach for optimal design of the robot. The paper shows a path to follow to design the robot taking into account a maximum workspace with dexterity. We present two study cases to test the performance of the proposed approach.Los robot planos pueden realizar tareas industriales como el corte X-Y. En este sentido, el robot paralelo plano de 2 Grados de Libertad (GdL) y 5 pares de revoluta (R) puede ser empleado como concepto de diseño. Un robot paralelo está conformado por varias cadenas cinemáticas cerradas, lo que le da una estructura que permite una mejor distribución de las cargas soportadas. Los robots paralelos presumen características ventajosas en cuanto a la relación peso del robot y peso de la carga soportada,  tienen mayor velocidad, rigidez y precisión. Como principal contrapartida, los robots paralelos tienen un espacio de trabajo reducido. En este trabajo, se busca diseñar un robot plano de 2GdL 5R de forma tal que su espacio de trabajo sea el máximo posible y que además presente óptima destreza. Para ello, se toma ventaja de la  técnica de optimización Algoritmos Genéticos (AG) y se desarrolla un procedimiento numérico para optimizar el espacio de trabajo y la agilidad con que el robot puede moverse (destreza). Dos casos de estudio ejemplifican la implementación del procedimiento propuesto

Kinematic Modelling and Simulation of 3-Axis Robotic Arm for Performing Welding Operations with Arbitarary Weld Joint Profiles

Robot welding is a fast and accurate welding to obtain a good joint strength. In this thesis, a 3-axis robotic arm has been modeled using CAD tool for performing welding operations. For the developed robotic arm, forward & inverse kinematic analyses have been performed to move the weld torch in the desired trajectory. A new seam tracking methodology, named sewing technique has been introduced for the welded joints available in Computer Aided Design (CAD) environment. This methodology, gives the seam path by drawing a line through the adjacent centroids of curve fitted in the weld joint volume. Obtained geometric path and kinematic constraints are given as input to the modeled robot for performing welding operation followed by desired trajectory. Validation of the developed methodology has been done through simulation results while performing welding operations for different weld profiles

Diseño e implementación de una plataforma robótica tipo delta

El objetivo principal de esta investigación es diseñar e implementar un prototipo de un robot Delta, solucionando los problemas de espacio de trabajo reducido y gran número de singularidades, optimizando las dimensiones de sus eslabones para maximizar su espacio de trabajo y su destreza. Adicionalmente, se desarrollan los modelos cinemáticos directo e inverso y se implementan en una interfaz gráfica de usuario para controlar los movimientos del robot desde un computador.Pregrad

Design and Development of an Automated Mobile Manipulator for Industrial Applications

This thesis presents the modeling, control and coordination of an automated mobile manipulator. A mobile manipulator in this investigation consists of a robotic manipulator and a mobile platform resulting in a hybrid mechanism that includes a mobile platform for locomotion and a manipulator arm for manipulation. The structural complexity of a mobile manipulator is the main challenging issue because it includes several problems like adapting a manipulator and a redundancy mobile platform at non-holonomic constraints. The objective of the thesis is to fabricate an automated mobile manipulator and develop control algorithms that effectively coordinate the arm manipulation and mobility of mobile platform. The research work starts with deriving the motion equations of mobile manipulators. The derivation introduced here makes use of motion equations of robot manipulators and mobile platforms separately, and then integrated them as one entity. The kinematic analysis is performed in two ways namely forward & inverse kinematics. The motion analysis is performed for various WMPs such as, Omnidirectional WMP, Differential three WMP, Three wheeled omni-steer WMP, Tricycle WMP and Two steer WMP. From the obtained motion analysis results, Differential three WMP is chosen as the mobile platform for the developed mobile manipulator. Later motion analysis is carried out for 4-axis articulated arm. Danvit-Hartenberg representation is implemented to perform forward kinematic analysis. Because of this representation, one can easily understand the kinematic equation for a robotic arm. From the obtained arm equation, Inverse kinematic model for the 4-axis robotic manipulator is developed. Motion planning of an intelligent mobile robot is one of the most vital issues in the field of robotics, which includes the generation of optimal collision free trajectories within its work space and finally reaches its target position. For solving this problem, two evolutionary algorithms namely Particle Swarm Optimization (PSO) and Artificial Immune System (AIS) are introduced to move the mobile platform in intelligent manner. The developed algorithms are effective in avoiding obstacles, trap situations and generating optimal paths within its unknown environments. Once the robot reaches its goal (within the work space of the manipulator), the manipulator will generate its trajectories according to task assigned by the user. Simulation analyses are performed using MATLAB-2010 in order to validate the feasibility of the developed methodologies in various unknown environments. Additionally, experiments are carried out on an automated mobile manipulator. ATmega16 Microcontrollers are used to enable the entire robot system movement in desired trajectories by means of robot interface application program. The control program is developed in robot software (Keil) to control the mobile manipulator servomotors via a serial connection through a personal computer. To support the proposed control algorithms both simulation and experimental results are presented. Moreover, validation of the developed methodologies has been made with the ER-400 mobile platform

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