Configuration switch and path selection between Schönflies motion and non-Schönflies motion based on quotient manifold of novel reconfigurable parallel mechanisms

Abstract

This paper investigates configuration switch and path selection of novel reconfigurable parallel mechanisms with two double-four-bar modular linkages in terms of subgroups SE(2), SO(3) and X(z). The motion representation of reconfigurable parallel mechanisms with three motion branches is proposed based on intersection operation of manifold generated, and the switching principle of motion generators is presented to realize the switching of the three motion branches of the reconfigurable parallel mechanism through the transformation of the submanifold generated by the suitable common motion generators. Two double-four-bar modular linkages are designed to constitute a subchain in terms of the switching principle, and the configuration transformation of the subchain is proposed with respects to the configuration switch of each modular linkage following different forms of the quotient submanifold generated. A reconfigurable parallel mechanism is synthesized by means of rearranging the configurations of two modular linkages of three identical subchains. Especially, the paths of three configurations of a reconfigurable parallel mechanism are selected to satisfy switching.