This article addresses parallel manipulators with fewer than six degrees of freedom, whose use may prove valuable in those applications in which a higher mobility is uncalled for. In particular, a family of 3-dof manipulators containing only revolute joints or at the most revolute and prismatic ones is studied. Design and assembly conditions sufficient to provide the travelling platform with a pure translational motion are determined and two sub-families that fulfill the imposed constraint are found: one is already known in the literature, while the other is original. The new architecture does not exhibit rotation singularities, i.e., configurations in which the platform gains rotational degrees of freedom. A geometric interpretation of the translation singularities is provided.

1.
Gough, V. E., and Whitehall, S. G., 1962, “Universal Tyre Test Machine,” Proc. of the 9th International Congress of F.I.S.I.T.A., Vol. 117, pp. 117–135.
2.
Stewart
,
D.
,
1965
, “
A Platform with Six Degrees of Freedom
,”
Proc. Inst. Mech. Eng.
180
(
15
), pp.
371
386
.
3.
Innocenti
,
C.
, and
Parenti-Castelli
,
V.
,
1993
, “
Echelon Form Solution of Direct Kinematics for the General Fully-Parallel Spherical Wrist
,”
Mech. Mach. Theory
,
28
(
4
), pp.
553
561
.
4.
Gosselin
,
C. M.
, and
Lavoie
,
E.
,
1993
, “
On the Kinematic Design of Spherical Three-Degree-of-Freedom Parallel Manipulators
,”
Int. J. Robot. Res.
,
12
(
4
), pp.
394
402
.
5.
Gosselin
,
C. M.
,
Sefrioui
,
J.
, and
Richard
,
M. J.
,
1994
, “
On the Direct Kinematics of Spherical Three-Degree-of-Freedom Parallel Manipulators of General Architecture
,”
ASME J. Mech. Des.
,
116
(
2
), pp.
594
598
.
6.
Vischer
,
P.
, and
Clavel
,
R.
,
2000
, “
Argos: a Novel 3-DOF Parallel Wrist Mechanism
,”
Int. J. Robot. Res.
,
19
(
1
), pp.
5
11
.
7.
Karouia, M., and Herve´, J. M., 2000, “A Three-DOF Tripod for Generating Spherical Rotation,” Advances in Robot Kinematics, J. Lenarcˇicˇ and M. M. Stanisˇicˇ, eds., Kluwer Academic Publishers, pp. 395–402.
8.
Lee
,
K. M.
, and
Shah
,
D. K.
,
1988
, “
Kinematic Analysis of a Three-Degrees-of-Freedom In-Parallel Actuated Manipulator
,”
IEEE J. Rob. Autom.
,
4
(
3
), pp.
354
360
.
9.
Waldron
,
K. J.
,
Raghavan
,
M.
, and
Roth
,
B.
,
1989
, “
Kinematics of a Hybrid Series-Parallel Manipulation System
,”
ASME J. Dyn. Syst., Meas., Control
,
111
(
2
), pp.
211
221
.
10.
Carretero
,
J. A.
,
Podhorodeski
,
R. P.
,
Nahon
,
M. A.
, and
Gosselin
,
C. M.
,
2000
, “
Kinematic Analysis and Optimization of a New Three Degree-of-Freedom Spatial Parallel Manipulator
,”
ASME J. Mech. Des.
,
122
(
1
), pp.
17
24
.
11.
Clavel, R., 1988, “Delta, a Fast Robot With Parallel Geometry,” Proc. of the 18th International Symposium on Industrial Robots, Lausanne, Switzerland, pp. 91–100.
12.
Herve´, J. M., and Sparacino, F., 1991, “Structural Synthesis of Parallel Robots Generating Spatial Translation,” Proc. of the 5th IEEE Int. Conference on Advanced Robotics, Pisa, Italy, pp. 808–813.
13.
Herve´, J. M., and Sparacino, F., 1992, “STAR, a New Concept in Robotics,” Proc. of the 3rd Int. Workshop on Advances in Robot Kinematics, Ferrara, Italy, pp. 176–183.
14.
Herve´, J. M., 1995, “Design of Parallel Manipulators Via the Displacement Group,” Proc. of the 9th World Congress on the Theory of Machines and Mechanisms, Milan, Italy, pp. 2079–2082.
15.
Arai, T., Herve´, J. M., and Tanikawa, T. 1996, “Development of 3 DOF Micro Finger,” Proc. of the 1996 IEEE/RSJ Int. Conference on Intelligent Robots and Systems, Osaka, Japan, pp. 981–987.
16.
Tsai, L. W., and Stamper, R. E., 1996, “A Parallel Manipulator with Only Translational Degrees of Freedom,” MECH-1152, Proc. of the 1996 ASME Design Engineering Technical Conferences, Irvine, CA.
17.
Wenger, P., and Chablat, D., 2000, “Kinematic Analysis of a New Parallel Machine Tool: the Orthoglide,” Advances in Robot Kinematics, J. Lenarcˇicˇ and M. M. Stanisˇic´, eds., Kluwer Academic Publishers, pp. 305–314.
18.
Zhao, T. S., and Huang, Z., 2000, “A Novel Three-DOF Translational Platform Mechanism and Its Kinematics,” MECH-14101, Proc. of the 2000 ASME Design Engineering Technical Conferences, Baltimore, MD.
19.
Tsai, L. W., 1996, “Kinematics of a Three-DOF Platform with Three Extensible Limbs,” Recent Advances in Robot Kinematics, J. Lenarcˇicˇ and V. Parenti-Castelli, eds., Kluwer Academic Publishers, pp. 401–410.
20.
Clavel, R., 1990, “Device for the Movement and Positioning of an Element in Space,” United States Patent No. 4,976,582.
21.
Di Gregorio, R., and Parenti-Castelli, V., 1998, “A Translational 3-DOF Parallel Manipulator,” Advances in Robot Kinematics: Analysis and Control, J. Lenarcˇicˇ and M. L. Husty, eds., Kluwer Academic Publishers, pp. 49–58.
22.
Tsai
,
L. W.
, and
Joshi
,
S.
,
2000
, “
Kinematics and Optimization of a Spatial 3-UPU Parallel Manipulator
,”
ASME J. Mech. Des.
,
122
(
4
), pp.
439
446
.
23.
Frisoli, A., Checcacci, D., Salsedo, F., and Bergamasco, M., 2000, “Synthesis by Screw Algebra of Translating In-Parallel Actuated Mechanisms,” Advances in Robot Kinematics, J. Lenarcˇicˇ and M. M. Stanisˇic´, eds., Kluwer Academic Publishers, pp. 433–440.
24.
Di Gregorio, R., and Parenti-Castelli, V., 1999, “Mobility Analysis of the 3-UPU Parallel Mechanism Assembled for a Pure Translation Motion,” Proc. of the 1999 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, Atlanta, GA, pp. 520–525.
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