Stiffness Analysis of Parallel Manipulators with Preloaded Passive Joints

Anatol Pashkevich (1) , Alexandr Klimchik (1) , Damien Chablat (1)

1 IRCCyN - Institut de Recherche en Communications et en Cybernétique de Nantes

The paper presents a methodology for the enhanced stiffness analysis of parallel manipulators with internal preloading in passive joints. It also takes into account influence of the external loading and allows computing both the non-linear ``load-deflection'' relation and the stiffness matrices for any given location of the end-platform or actuating drives. Using this methodology, it is proposed the kinetostatic control algorithm that allows to improve accuracy of the classical kinematic control and to compensate position errors caused by elastic deformations in links/joints due to the external/internal loading. The results are illustrated by an example that deals with a parallel manipulator of the Orthoglide family where the internal preloading allows to eliminate the undesired buckling phenomena and to improve the stiffness in the neighborhood of its kinematic singularities.

Mots clés: modeling; parallel manipulators; external loading; internal Mreloading; passive joints

Domaines: Robotique [cs.RO]

Anatol Pashkevich, Alexandr Klimchik, Damien Chablat. Stiffness Analysis of Parallel Manipulators with Preloaded Passive Joints. 12th International Symposium on Advances in Robot Kinematics, Jun 2010, Ljubljana, Slovenia. pp.465-474. ⟨hal-00544851⟩