Generation of Architecturally Singular 6-SPS Parallel Manipulators with Linearly Related Planar Platforms

Abstract

An architecturally singular parallel manipulator is a parallel manipulator with architectural singularities spanning the whole workspace. It should be abandoned in the design process. This paper deals with the generation of architecturally singular 6-SPS parallel manipulators with linearly related planar platforms. The forward displacement analysis of the 6-SPS parallel manipulator with linearly related planar platforms is performed at first. All the architecturally singular 6-SPS parallel manipulators with linearly related planar platforms are then generated. It is found that a 6-SPS parallel manipulator with linearly related planar platforms is architecturally singular if and only if all the spherical joints on the base (or moving platform ) are located on a conic section. At last, self-motion analysis of the architecturally singular 6-SPS parallel manipulators with linearly related planar platforms is addressed