Kinematic analysis of a novel 3-CRU translational parallel mechanism
In this paper, a modified 3-DOF (degrees of freedom) translational parallel mechanism (TPM) three-CRU (C, R, and U represent the cylindrical, revolute, and universal joints, respectively) structure is proposed. The architecture of the TPM is comprised of a moving platform attached to a base through...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2015-04-01
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Series: | Mechanical Sciences |
Online Access: | http://www.mech-sci.net/6/57/2015/ms-6-57-2015.pdf |
Summary: | In this paper, a modified 3-DOF (degrees of freedom) translational
parallel mechanism (TPM) three-CRU (C, R, and U represent the cylindrical,
revolute, and universal joints, respectively) structure is proposed. The
architecture of the TPM is comprised of a moving platform attached to a base
through three CRU jointed serial linkages. The
prismatic motions of the cylindrical joints are considered to be actively
actuated. Kinematics and performance of the TPM are studied systematically.
Firstly, the structural characteristics of the mechanism are described, and
then some comparisons are made with the existing 3-CRU parallel mechanisms.
Although these two 3-CRU parallel mechanisms are both composed of the same
CRU limbs, the types of freedoms are completely different due to the
different arrangements of limbs. The DOFs of this TPM are analyzed by means of
screw theory. Secondly, both the inverse and forward displacements are
derived in closed form, and then these two problems are calculated directly
in explicit form. Thereafter, the Jacobian matrix of the mechanism is
derived, the performances of the mechanism are evaluated based on the
conditioning index, and the performance of a 3-CRU TPM changing with the
actuator layout angle is investigated. Thirdly, the workspace of the
mechanism is obtained based on the forward position analysis, and the
reachable workspace volume is derived when the actuator layout angle is
changed. Finally, some conclusions are given and the potential applications
of the mechanism are pointed out. |
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ISSN: | 2191-9151 2191-916X |