Design and Prototyping of a New Balancing Mechanism for Spatial Parallel Manipulators

Cédric Baradat (1) , Vigen Arakelian (2) , Sébastien Briot (3) , Sylvain Guegan (4)

1 Fatronik France
2 DGMA - Département de Génie Mécanique et Automatique
3 IRCCyN - Institut de Recherche en Communications et en Cybernétique de Nantes
4 LGCGM - Laboratoire de Génie Civil et Génie Mécanique

This paper proposes a new solution to the problem of torque minimization of spatial parallel manipulators. The suggested approach involves connecting a secondary mechanical system to the initial structure, which generates a vertical force applied to the manipulator platform. Two versions of the added force are considered: constant and variable. The conditions for optimization are formulated by the minimization of the root-mean-square values of the input torques. The positioning errors of the unbalanced and balanced parallel manipulators are provided. It is shown that the elastic deformations of the manipulator structure which are due to the payload, change the altitude and the inclination of the platform. A significant reduction of these errors is achieved by using the balancing mechanism. The efficiency of the suggested solution is illustrated by numerical simulations and experimental verifications. The prototype of the suggested balancing mechanism for the Delta robot is also presented.

Mots clés: Index terms -balancing; torque compensation; parallel mechanisms; Delta robot

Domaines: Génie mécanique [physics.class-ph]; Génie mécanique [physics.class-ph]

Cédric Baradat, Vigen Arakelian, Sébastien Briot, Sylvain Guegan. Design and Prototyping of a New Balancing Mechanism for Spatial Parallel Manipulators. Journal of Mechanical Design, 2008, 130 (7). ⟨hal-00451887⟩