Structure synthesis of reconfigurable parallel mechanisms with closed-loop metamorphic linkages

Abstract

This paper proposes a class of closed-loop metamorphic linkages, which has different phases resulting from links annexing or locking of motors. Reconfigurable limbs are obtained by assembling these metamorphic linkages with kinematic chains. The potential metamorphic linkages are presented and the working phase transformation of the metamorphic linkages is analyzed. After adding suitable kinematic joints to the metamorphic linkage, the reconfigurable limbs whose constraint can be switched among different constraint forces and couples are synthesized. The serial limbs that can provide u ( u = 0, 1, 2) constraint forces and v ( v = 0, 1, 2) constraint couples are constructed by using screw theory method. The reconfigurable limbs which possess different configurations are combined with serial kinematic chains. By connecting the end moving platform to the fixed base with three identical kinematic limbs, a family of reconfigurable mechanisms with closed-loop metamorphic linkages is derived. These mechanisms have various output motion modes, such as 3R, 1T2R, 2T1R, and 3T.

Research on the Type Synthesis of a Regular Hexagonal Prism Rubik’s Cube Mechanism

“…Leveraging the reconfigurable characteristics of the bending rod group, a coupled-motion relationship between two bending rod groups was established. Whether through the introduction of a limb chain with constraint singularity [36], the utilization of a reconfigurable kinematic pair [37], the locking of a kinematic pair [38], etc., these approaches can be considered indirect methods for conducting the type synthesis of reconfigurable mechanisms.…”

A novel reconfigurable parallel mechanism constructed with spatial metamorphic four-link mechanism

“…Tian synthesized a kind of reconfigurable parallel mechanism based on the closed chain of metamorphic single ring. 30,31 Based on Bennett closed chain to construct a hybrid limb, Zhang proposed a new type of metamorphic parallel mechanism. 32 The typical metamorphic joints are vA joint with three different substructures, S V , U V , and R V , 33,34 and rT joint with two different subphases.…”