Configuration Change and Mobility Analysis of a Novel Metamorphic Parallel Mechanism Constructed with (rA) Joint

Abstract

This paper presents a unique feature of geometric and physical constraint of axes of the reconfigurable-axis (rA) joint and analyses the effectiveness in the constructed limb, resulting in variation of mobility configuration of metamorphic parallel mechanism. This change in mobility is completed by two cases illustrated by a 3(rA)PS metamorphic parallel mechanism having variable mobility from 3 to 6. The underlying principle of the metamorphosis of this rA joint is demonstrated by investigating the dependence of the corresponding screw system comprising of line vectors, leading to evolution of the rA joint from the two types of spherical joints to the three types of variable Hooke joints and the one revolute joint. This new type of metamorphic parallel mechanism has broad application prospects, especially in the field of 3d printing. According to the complexity of the shape of the workpiece, the degree of freedom corresponding to different topologies can be selected, which can reduce the costs and increase the adaptability to different working conditions.