... in an arbitrary (possibly singular) reference configuration. This algorithm involves screw products of constant screw vectors only. Unlike the Lie group methods for estimating the DOF of so-called exceptional linkages, this method does not rely on partitioning kinematic loops into partial kinematic chains...

...Andreas Müller; P.C. López-Custodio; J.S. Dai The local analysis is an established approach to the study of singularities and mobility of linkages. The key result of such analyses is a local picture of the finite motion through a configuration. This reveals the finite mobility at that point...

... manuscript received December 11, 2012; published online January 25, 2013. Assoc. Editor: Yuefa Fang. 20 09 2012 11 12 2012 planar parallel manipulators design effort transmission transmission angle singularities Parallel manipulators have many...

... changing motion, which increases the maximum singularity-free workspace. An accurate algorithm for the determination is proposed amending some imprecisions done by previous existing algorithms. This is combined with methods of cylindric algebraic decomposition, Gröbner bases, and discriminant varieties...

...Michel Coste Avoiding singularities in the workspace of a parallel robot is an important issue. The case of 3-RPR planar robots is an important subject of theoretical studies. We study the singularities of planar 3-RPR robots by using a new parameterization of the singular locus in a modified...

...Andreas Müller Whether the singularities of a kinematic mapping constitute smoothmanifolds is an important question with significance to mechanism design and robot control. It is thus obvious to ask if this is generically so. In a preceding paper, two kinematically meaningful genericity concepts...

...Andreas Müller It is commonly assumed that the singularities of kinematic mappings constitute generically smooth manifolds but this has not yet been proven. Moreover, before this assumption can be verified, the concept of genericity needs to be clarified. In this paper, two different notions...