Special cases of Schönflies-singular planar Stewart Gough platforms

Abstract

Parallel manipulators which are singular with respect to the Schönflies motion group X(a) are called Schönflies-singular, or more precisely X(a)-singular, where a denotes the rotary axis. A special class of such manipulators are architecturally singular ones because they are singular with respect to any Schönflies group. Another remarkable set of Schönflies-singular planar Stewart Gough platforms was already presented by the author in [5].Moreover the main theorem on these manipulators was given in [6]. In this paper we give a complete discussion of the remaining special cases which also include so-called Cartesian-singular planar manipulators as byproduct. © Springer Science+Business Media B.V. 2010.