Singular curves and cusp points in the joint space of 3-RPR parallel manipulators

Mazen Zein (1) , Philippe Wenger (1) , Damien Chablat (1)

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

This paper investigates the singular curves in two-dimensional slices of the joint space of a family of planar parallel manipulators. It focuses on special points, referred to as cusp points, which may appear on these curves. Cusp points play an important role in the kinematic behavior of parallel manipulators since they make possible a nonsingular change of assembly mode. The purpose of this study is twofold. First, it reviews an important previous work, which, to the authors' knowledge, has never been exploited yet. Second, it determines the cusp points in any two-dimensional slice of the joint space. First results show that the number of cusp points may vary from zero to eight. This work finds applications in both design and trajectory planning.

Mots clés: Singular curves; cusp point; joint space; assembly mode; 3-RPR parallel manipulator

Domaines: Robotique [cs.RO]

Mazen Zein, Philippe Wenger, Damien Chablat. Singular curves and cusp points in the joint space of 3-RPR parallel manipulators. 2006, Orlando, United States. pp.1-6. ⟨hal-00160809⟩