Synthesis and Design of a Novel 3T1R Fully-Parallel Manipulator

Abstract

In this paper a new topology of four degrees-of-freedom 3T1R fully-parallel manipulator is presented, which is defined only using lower kinematic pairs. The paper starts with a complete type synthesis of different topologies of fully-parallel manipulators that can perform the so-called Schönflies motion, based on the Theory of Groups of Displacements. After imposing some practical requirements, the different possibilities of manipulators are reduced to only one topology of fully-parallel and fully-symmetrical parallel manipulator. Then, the kinematic analysis of the manipulator is shown, including the closed-form resolution of both forward and inverse position problems, the velocity and the singularity analysis. Finally, a prototype of the manipulator is presented, which is intended to be used in pick and place applications.

Type synthesis of primitive Schoenflies-motion generators

“…In the chapter ''Special motions" of their book ''Theoretical Kinematics" [13], Bottema and Roth reported this special motion type as ''Schoenflies motion" in a manner that is also independent of group theory. This motion type considered as being a set of point transformations will be simply termed X-motion for the sake of conciseness, whose designation was also used in the already published works [4,8,[21][22][23]. A specified X-motion is a 4D displacement Lie subgroup, which contains any translation and any rotation provided that the axis of rotation is parallel to a given direction.…”

Análisis Cinemático del Manipulador Paralelo 4- P RUR Mediante la Teoría de Tornillos

“…Por otro lado, tradicionalmente se ha resuelto el análisis de velocidad obteniendo el jacobiano diferenciando las ecuaciones de restricción o las de lazo vectorial del análisis de posición (Richard et al, 2007;Salgado et al, 2008;Lee and Lee, 2016). Algunos autores plantean este análisis mediante el uso de la teoría de tornillos (Kim et al, , 2014Solazzi et al, 2014) aunque la matriz jacobiana resulta no ser cuadrada, lo que dificulta la obtención de una ecuación de entrada/salida de velocidad de forma simple y compacta.…”

Type synthesis and kinematic analysis of a new class Schönflies motion parallel manipulator

“…Briot et al [14]- [16] provide a Schönflies motion solution by using pantographs, which is a great advantage in terms of workspace volume and acceleration capacities. Salgado et al [17][18] proposed a practical 3T1R type parallel mechanisms with identical four chains. A similar design is proposed by Kim [19], this work demonstrates that connecting the four chains to the top platform asymmetrically helps avoiding architectural singularity.…”