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arXiv · 0808.1247

Self-Motions of General 3-RPR Planar Parallel Robots

Sébastien Briot·Ilian Bonev·Damien Chablat·Philippe Wenger·Vigen Arakelian
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Abstract

This paper studies the kinematic geometry of general 3-RPR planar parallel robots with actuated base joints. These robots, while largely overlooked, have simple direct kinematics and large singularity-free workspace. Furthermore, their kinematic geometry is the same as that of a newly developed parallel robot with SCARA-type motions. Starting from the direct and inverse kinematic model, the expressions for the singularity loci of 3-RPR planar parallel robots are determined. Then, the global behaviour at all singularities is geometrically described by studying the degeneracy of the direct kinematic model. Special cases of self-motions are then examined and the degree of freedom gained in such special configurations is kinematically interpreted. Finally, a practical example is discussed and experimental validations performed on an actual robot prototype are presented.

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Sébastien Briot, Ilian Bonev, Damien Chablat, Philippe Wenger, Vigen Arakelian. 2008-08-08. Self-Motions of General 3-RPR Planar Parallel Robots. https://doi.org/10.1177/0278364908092466

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