Reconfiguration Analysis of a 3-DOF Parallel Mechanism

Abstract

This paper deals with the reconfiguration analysis of a 3-DOF (degrees-of-freedom) parallel manipulator (PM) which belongs to the cylindrical parallel mechanisms family. The PM is composed of a base and a moving platform shaped as equilateral triangles connected by three serial kinematic chains (legs). Two legs are composed of two universal (U) joints connected by a prismatic (P) joint. The third leg is composed of a revolute (R) joint connected to the base, a prismatic joint and universal joint in sequence. A set of constraint equations of the 1-RPU−2-UPU PM is derived and solved in terms of the Euler parameter quaternion (a.k.a. Euler-Rodrigues quaternion) representing the orientation of the moving platform and of the Cartesian coordinates of the reference point on the moving platform. It is found that the PM may undergo either the 3-DOF PPR or the 3-DOF planar operation mode only when the base and the moving platform are identical. The transition configuration between the operation modes is also identified.

Configuring a Class of Machines Based on Reconfigurable 2DOF Planar Parallel Mechanism

“…), many researches are focused on the analysis and configuring of parallel mechanisms to define the optimal mechanism configuration for the intended application. The most analyzed parallel mechanisms are 2DOF planar mechanisms [8][9][10], 3DOF planar mechanisms [11][12][13] and 3DOF spatial parallel mechanisms [14][15][16]. As can be seen, even if the geometry of mechanisms is relatively simple, the analysis and configuration of the mechanism is complex.…”