Optimal design of a 2-DOF pick-and-place parallel robot using dynamic performance indices and angular constraints

This paper presents an approach for the optimal design of a 2-DOF translational pick-and-place parallel robot. By taking account of the normalized inertial and centrifugal/Coriolis torques of a single actuated joint, two global dynamic performance indices are proposed for minimization. The pressure angles within a limb and between two limbs are considered as the kinematic constraints to prevent direct and indirect singularities. These considerations together form a multi-objective optimization problem that can then be solved by the modified goal attainment method. A numerical example is discussed. A number of robots designed by this approach have been integrated into production lines for carton packing in the pharmaceutical industry

Optimal design of a 2-DOF pick-and-place parallel robot using dynamic performance indices and angular constraints

This paper presents an approach for the optimal design of a 2-DOF translational pick-and-place parallel robot. By taking account of the normalized inertial and centrifugal/Coriolis torques of a single actuated joint, two global dynamic performance indices are proposed for minimization. The pressure angles within a limb and between two limbs are considered as the kinematic constraints to prevent direct and indirect singularities. These considerations together form a multi-objective optimization problem that can then be solved by the modified goal attainment method. A numerical example is discussed. A number of robots designed by this approach have been integrated into production lines for carton packing in the pharmaceutical industry

Manipulator Performance Measures - A Comprehensive Literature Survey

Due to copyright restrictions of the publisher this item is embargoed and access to the file is restricted until a year after the publishing date.The final publication is available at www.springerlink.comPerformance measures are quintessential to the design, synthesis, study and application of robotic manipulators. Numerous performance measures have been defined to study the performance and behavior of manipulators since the early days of robotics; some more widely accepted than others, but their real significance and limitations have not always been well understood. The aim of this survey is to review the definition, classification, scope, and limitations of some of the widely used performance measures. This work provides an extensive bibliography that can be of help to researchers interested in studying and evaluating the performance and behavior of robotic manipulators. Finally, a few recommendations are proposed based on the review so that the most commonly noticed limitations can be avoided when new performance measures are proposed.http://link.springer.com/article/10.1007/s10846-014-0024-y

Robotic prototyping environment (Progress report)

Journal ArticlePrototyping is an important activity in engineering. Prototype development is a good test for checking the viability of a proposed system. Prototypes can also help in determining system parameters, ranges, or in designing better systems. The interaction between several modules (e.g., S/W, VLSI, CAD, CAM, Robotics, and Control) illustrates an interdisciplinary prototyping environment that includes radically different types of information, combined in a coordinated way. Developing an environment that enables optimal and flexible design of robot manipulators using reconfigurable links, joints, actuators, and sensors is an essential step for efficient robot design and prototyping. Such an environment should have the right "mix" of software and hardware components for designing the physical parts and the controllers, and for the algorithmic control of the robot modules (kinematics, inverse kinematics, dynamics, trajectory planning, analog control and digital computer control). Specifying object-based communications and catalog mechanisms between the software modules, controllers, physical parts, CAD designs, and actuator and sensor components is a necessary step in the prototyping activities. We propose a flexible prototyping environment for robot manipulators with the required sub-systems and interfaces between the different components of this environment

Robot manipulator prototyping (Complete Design Review)

Journal ArticlePrototyping is an important activity in engineering. Prototype development is a good test for checking the viability of a proposed system. Prototypes can also help in determining system parameters, ranges, or in designing better systems. The interaction between several modules (e.g., S/W, VLSI, CAD, CAM, Robotics, and Control) illustrates an interdisciplinary prototyping environment that includes radically different types of information, combined in a coordinated way. Developing an environment that enables optimal and flexible design of robot manipulators using reconfigurable links, joints, actuators, and sensors is an essential step for efficient robot design and prototyping. Such an environment should have the right "mix" of software and hardware components for designing the physical parts and the controllers, and for the algorithmic control of the robot modules (kinematics, inverse kinematics, dynamics, trajectory planning, analog control and digital computer control). Specifying object-based communications and catalog mechanisms between the software modules, controllers, physical parts, CAD designs, and actuator and sensor components is a necessary step in the prototyping activities. We propose a flexible prototyping environment for robot manipulators with the required subsystems and interfaces between the different components of this environment

Parcours continus isotropes et surfaces isotropes de manipulateurs sériels

RÉSUMÉ Cette thèse traite des manipulateurs sériels en tant que chaînes cinématiques ouvertes simples. Plus précisément ce sont les parcours continus sur lesquels de tels manipulateurs gardent constamment une configuration isotrope qui sont l’objet de l’étude. La capacité d’un manipulateur à orienter et à déplacer son effecteur est un point déterminant pour la réalisation de tâches. Plus cette capacité est grande, meilleure sera la possibilité de réalisation des travaux par le manipulateur. La capacité maximale est atteinte à des configurations dites isotropes. Jusqu’à récemment, les seules configurations isotropes atteignables par les manipulateurs étaient des configurations isolées, ou des configurations que nous qualifions de triviales, c’est-à-dire des configurations issues de la rotation de la première articulation. L’apport nouveau de ce travail de recherche est de prouver l’existence de parcours isotropes non triviaux. Ainsi, plusieurs manipulateurs peuvent effectuer des tâches sur des parcours non ponctuels ou non circulaires avec une dextérité accrue loin des singularités. Des manipulateurs sériels ayant non seulement des parcours isotropes continus ont été déterminés, mais aussi des manipulateurs ayant des surfaces isotropes. Ces surfaces isotropes sont déterminées pour des manipulateurs sphériques et non sphériques. L’isotropie d’orientation et l’isotropie de position sont étudiées séparément, puis simultanément. Les différentes définitions de la dextérité des manipulateurs proposées depuis plus de deux décennies trouvent aussi par ce travail l’occasion d’un nouvel éclairage à travers le concept des articulations virtuelles introduites dans les chapitres 4 et 5. Le chapitre 2, qui fait suite à l’introduction et à la revue de littérature, traite du conditionnement et de l’isotropie. La plupart des résultats et exemples qui y sont exposés sont puisés dans la littérature et visent à montrer l’importance de ces notions qui sont utilisées comme fondement de ce travail de recherche.----------ABSTRACT This thesis deals with serial manipulators as simple opened kinematics chains.These are more precisely the continuous paths, upon which such manipulators always keep an isotropic configuration,that are the subject of the study. The capacity of a manipulator to direct and move its effector is a decisive point in carrying out tasks. Bigger is this capacity better will be the possibility for the manipulator to carry out tasks. The maximal capacity is reached for isotropic configurations. Until recently, the only reachable isotropic configurations by manipulators were isolated configurations, or configurations that we call trivial which means they result from the rotation of the first joint. The contribution of this thesis is to prove the existence of non trivial isotropic paths. Thus, many manipulators can perform tasks on non punctual or non circular paths with an improved dexterity far from singularities. Not only serials manipulators with contiunous isotropic paths have been found, but also manipulators with isotropic surfaces. These isotropic surfaces are determined for spherical and non spherical manipulators. The isotropy of orientation and isotropy of position are studied separately, then simultaneously. Through the concept of virtual joints introduced in chapter 4 and 5, this work is also the opportunity to bring a new clarification on the various definitions of manipulators dexterity that have been proposed for more than two decades. The chapter 2 which ensue from the introduction and related works deals with the conditioning and the isotropy. Most of the expounded results and examples are draged from related papers and aim at showing the importance of these notions which are used as a basis of this research. The chapter 3 proves an important result: the non existence of non trivial continuous isotropic paths for spherical manipulators with less than 6 joints

Design, dynamics and control of a fast two-wheeled quasiholonomic robot

The control of wheeled mobile robots is particularly challenging because of the presence of nonholonomic constraints. Modern two-wheeled mobile robot control is further complicated by the presence of one unstable equilibrium point, which requires a continuous stabilization of the intermediate body by means of sensors. In order to simplify the control of these systems, Quasimoro, a novel two-wheeled mobile robot, is proposed. The control of Quasimoro is simplified by means of its mechanical design. The robot is designed for quasiholonomy, a property that simplifies the control of nonoholonomic systems. To further simplify the control, the robot is designed so as to have a stable equilibrium point.A nonholonomic robotic mechanical system that can be rendered quasiholonomic by control is termed, in this thesis, quasiholonomic. This is the case of Quasimoro.This work proposes a model-based design methodology for wheeled mobile robots, intended to decrease the development costs, under which the prototype is built only when the system requirements are fully met. Following this methodology, the proposed robot is then designed and prototyped.The conceptual design of the robot is undertaken by means of a detailed analysis of the most suitable drive systems and their layout. The mathematical model of the robot is formulated in the framework of the Lagrange formalism, by resorting to the concept of holonomy matrix, while the controllability analysis is conducted using modern tools from geometric control.The embodiment design entails the simulation of three virtual prototypes aimed at further simplifying the robot control. To this end, a robot drive system, based on the use of a timing belt transmission and a bicycle wheel, is designed, calibrated and tested. Due to Quasimoro's drive system, the stabilization of the intermediate body, a well-known challenge in two-wheeled mobile robot control, is achieved without the use of additional mechanical stabilizers---such as casters---or of sensors---such as gyros.The intended application of the proposed robot is the augmentation of wheelchair users, a field that tremendously benefits from the cost-effectiveness and control simplification of the system at hand. For purposes of validation, a full-scale proof-of-concept prototype of the robot is realized. Moreover, the robot functionality is demonstrated by means of motion control experiments