Pédagogie et recherche pour une bibliothèque numérique de machines et mécanismes au sein du projet européen thinkMotion

Ce projet pédagogique associe des étudiants de niveau BAC+3 à un travail de recherche dans le cadre du projet européen thinkMotion, future grande bibliothèque numérique libre sur le thème des machines et mécanismes. En effet, une bonne part du riche patrimoine mécanique européen tombe dans l'oubli. Or, nos jeunes concepteurs doivent mettre en pratique méthodes de conception et outils de CFAO sur des exemples concrets. Voici comment ils analysent brevets et ouvrages anciens, modélisent géométrie et cinématique des machines et produisent du contenu multimédia à l'aide d'outils TICE

An efficient approach to closed-loop shape control of deformable objects using finite element models

International audienceRobots are nowadays faced with the challenge of handling deformable objects in industrial operations. In particular, the problem of shape control, which aims at giving a specific deformation state to an object, has gained interest recently in the research community. Among the proposed solutions, approaches based on finite elements proved accurate and reliable but also complex and computationally-intensive. In order to mitigate these drawbacks, we propose a scheme for shape control that does not require to run a real-time simulation or to solve an implicit optimization problem for computing the control outputs. It is based on a partition of the nodal coordinates that allows deriving a control law directly from tangent stiffness matrices. This formulation is also coupled with the introduction of reduced finite element models. Simulation and experimental results in the context of linear deformable object manipulation demonstrate the interest of the proposed approach

Cartesian Stiffness Matrix Mapping of a Translational Parallel Mechanism with Elastic Joints

This paper is devoted to calculating the Cartesian stiffness matrix of a translational parallel manipulator with elastic joints. The calculation takes into account the contribution of the Jacobian variation because of the change of manipulator configuration due to the elasticity and it covers the entire theoretical workspace of the manipulator. Three kineto-static adimensional indices are proposed to measure the response of the manipulator in terms of stiffness