Reconfiguration Analysis of Wren Platform and Its Kinematic Variants Based on Reciprocal Screw Systems

10.6567/IFToMM.14TH.WC.OS8.022

K. Zhang；J. S. Dai

Reconfiguration ； Screw system ； Reciprocity ； Wren platform ； Equivalent mechanism

Proceedings of the 14th IFToMM World Congress

14th-4（2015 / 11 / 04）

237 - 242

英文

The reconfigurable mechanism has distinct capability of changing its motion characteristics such as motility and motion branches without structure reassembling and reconstruction. This paper investigates the phenomena of reconfiguration of the Wren platform and its kinematic variant with bifurcated motion branches. The kinematic structure of the Wren platform is recalled first for the purpose of geometric analysis. According to its geometry, disposition and analytical expression of constraints exerted on the platform by kinematic limbs are investigated in terms of reciprocity of screw systems. This leads to enumeration of kinematic limbs for constructing motion-equivalent mechanisms of the Wren platform. The constraint analysis of each mechanism reveals inherent properties of motion branch changes by passing a transitory position where constraint singularity occurs.