Based on the position and orientation characteristic (POC) set and the POC equations for serial mechanisms and parallel mechanisms proposed by authors, this paper presents a novel general degree of freedom (DOF) formula which is totally different from approaches based on the screw theory and the displacement group. It can be used to determine the full-cycle DOF of parallel mechanisms (PMs) and multiloop spatial mechanisms using symbolic “union” and “intersection” operations for POC sets. These operations involve only several rules and only simple mathematical tools (vector algebra, theory of sets, etc.) are used. Furthermore, criteria for determination of the inactive joints and selection of the actuating joints are proposed. The presented approach is illustrated with several examples.

References

1.
Chebychev
,
P. A.
, 1854, Théorie des mécanismes connus sous le nom de parallélogrammes, 1ére partie, Mémoires présentés ál Académie impériale des sciences de Saint-Pétersbourg par divers savants.
2.
Grubler
,
M.
, 1916,
Das Kriterium der Zwänglau.gkeit der Schraubenkelten, Festschrift, O. Mohr. Zum 80, Gubertstag
,
Julius Springer Verlag
,
Berlin
.
3.
Kutzbach
,
K.
, 1929, “
Mechanische Leitungsverzweigung, ihre Gesetze und Anwendungen
,”
Maschinenbau
,
8
, pp.
710
716
.
4.
Zhang
,
Q. X.
, 1961, “
Study on Structural Theory of Spatial Mechanisms
,”
Chinese. J. Mech. Eng.
,
9
(
1
), pp:
6
9
.
5.
Freudenstein
,
F.
, and
Alizade
,
R.
, 1975, “
On the Degree-of-Freedom of Mechanisms With Variable General Constraint
,” Fourth World Congress on the Theory of Machines and Mechanisms.
6.
Gogu
,
G.
, 2005, “
DOF of Mechanisms: A Critical Review
,”
Mech. Mach. Theory
,
40
, pp.
1068
1097
.
7.
Hunt
,
K. H.
, 1978,
Kinematic Geometry of Mechanisms
,
Oxford University Press
,
Oxford
.
8.
Davidson
,
J. K.
, and
Hunt
,
K. H.
, 2004,
Robots and Screw Theory: Application of Kinematics and Statics to Robotics
,
Oxford University Press
,
London
.
9.
Zhao
,
J. S.
,
Zhou
,
K.
, and
Feng
,
Z. J.
, 2004, “
Theory of Degrees of Freedom for Mechanisms
,”
Mech. Mach. Theory
,
39
, pp.
621
643
.
10.
Dai
,
J. S.
,
Huang
,
Z.
, and
Lipkin
,
H.
, 2005, “
DOF of Overconstrained Parallel Mechanisms
,”
ASME J. Mech. Des.
,
128
, pp.
220
229
.
11.
Huang
,
Z.
, 2004, “
The Kinematics and Type Synthesis of Lower-DOF Parallel Robot Manipulators
,”
Proceedings of the 11th World Congress in Mechanism and Machine Science
, Tianjin,
Vol.1
, pp.
65
76
.
12.
Kong
,
X. W.
, and
Gosselin
,
C. M.
, 2005, “
DOF Analysis of Parallel Mechanisms Based on Screw Theory and the Concept of Equivalent Serial Kinematic Chain
,”
Proceedings of the ASME Design Engineering Technical Conference
, Paper No. DETC2005-85337.
13.
Gogu
,
G.
, 2005, “
DOF and Spatiality of Parallel Robots Revisited via Theory of Linear Transformations
,”
Eur. J. Mech. A/Solids
,
24
, pp.
690
711
.
14.
Rico
,
J. M.
,
Gallardo
,
J.
, and
Ravani
,
B.
, 2003, “
The Lie Algebra and the DOF of Kinematic Chains
,”
J. Rob. Syst.
,
20
, pp.
477
499
.
15.
Rico
,
J. M.
,
Aguilera
,
L. D.
,
Gallardo
,
J.
,
Rodriguez
,
R.
,
Orozco
,
H.
, and
Barrera
,
J. M.
, 2006, “
A More General DOF Criterion for Parallel Platforms
,”
ASME J. Mech. Des.
,
128
, pp.
207
219
.
16.
Herve
,
J. M.
, 1978, “
Analyse Structurelle des Mecanismes par Groupe des Deplacements
,”
Mech. Mach. Theory
,
13
, pp.
437
450
.
17.
Fanghella
,
P.
, and
Galletti
,
C.
, 1994, “
DOF Analysis of Single-Loop Kinematic Chains: An Algorithmic Approach Based on Displacement Groups
,”
Mech. Mach. Theory
,
29
, pp.
1187
1204
.
18.
Fanghella
,
P.
, and
Galletti
,
C.
, 1995, “
Metric Relations and Displacement Groups in Mechanism and Robot Kinematics
,”
ASME J. Mech. Des.
,
117
, pp.
470
478
.
19.
Fanghella
,
P.
,
Galletti
,
C.
, and
Giannotti
,
E.
, 2006, “
Parallel Robots That Change Their Group of Motion
,”
Adv. Rob. Kin.
, Springer, Part I, pp.
49
56
.
20.
Li
,
Q.-C.
,
Huang
,
Z.
, and
Herve
,
J. M.
, 2004, “
Type Synthesis of 3R2T 5-DOF Parallel Mechanisms Using the Lie Group of Displacements
,”
IEEE Trans. Rob. Autom.
,
20
, pp.
173
180
.
21.
Rico Martinez
,
J. M.
, and
Ravani
,
B.
, 2003, “
On DOF Analysis of Linkages Using Group Theory
,”
ASME J. Mech. Des.
,
125
, pp.
70
80
.
22.
Rico
,
J. M.
,
Cervantes
,
J. J.
,
Rocha
,
J.
,
Gallardo
,
J.
,
Aguilera
,
L. D.
,
Perez
,
G. I.
, and
Tadeo
,
A.
,2007, “
DOF of Single Loop Linkages: A Final Word?
,”
Proceedings of ASME Mechanisms Conference
, Paper No. DETC2007-34936.
23.
Yang
,
T.-L.
,
Liu
,
A.-X.
,
Jin
,
Q.
,
Luo
,
Y.-F.
,
Shen
,
H.-P.
, and
Hang
,
L.-B.
, 2009, “
Position and Orientation Characteristic Equation for Topological Design of Robot Mechanisms
,”
ASME J. Mech. Des.
,
131
, pp:
021001
-
1
17.
24.
Yang
,
T.-L.
, 1983, “
Structural Analysis and Number Synthesis of Spatial Mechanisms
,”
Proceedings of the Sixth World Congress on Theory of Machines and Mechanisms
,
Vol.1
, pp.
280
283
.
25.
Yang
,
T.-L.
,
Jin
,
Q.
, 2001, “
Structural Synthesis of 4-DOF (3-Translational and 1-Rotation) Parallel Robot Mechanisms Based on the Unites of Single-Open-Chain
,”
The 27th Design Automation Conference
, Paper No. ASME DETC2001/DAC-21152.
26.
Yang
,
T.-L.
,
Jin
,
Q.
,
Liu
,
A.-X.
,
Shen
,
H.-P.
, and
Luo
,
Y.-F.
,2002, “
Structural Synthesis and Classification of the 3-DOF Translation Parallel Robot Mechanisms Based on the Unites of Single-Open Chain
,”
Chinese, J. Mech. Eng.
,
38
(
8
), pp.
31
36
.
27.
Jin
,
Q.
, and
Yang
,
T.-L.
, 2002, “
Over-Constraint Analysis on Spatial 6-Link Loops
,”
Mech. Mach. Th.
,
37
(
3
), pp.
267
278
.
28.
Jin
,
Q.
, and
Yang
,
T.-L.
, 2004, “
Theory for Topology Synthesis of Parallel Manipulators and Its Application to Three Dimension Translation Parallel Manipulators
,”
ASME J. Mech. Des.
,
126
, pp.
625
639
.
29.
Yang
,
T.-L.
, and
Sun
,
D.-J.
, 2006, “
General Formula of Degree of Freedom for Parallel Mechanisms and Its Application
,”
Proceedings of ASME 2006 Mechanisms Conference
, Paper No. DETC2006-99129.
30.
Yang
,
T.-L.
, and
Sun
,
D.-J.
, 2008, “
Rank and DOF of Single Loop Kinematic Chains
,”
Proceedings of the ASME 32nd Annual Mechanisms and Robotics Conference
, Paper No. DETC2008-49076.
31.
Yang
,
T.-L.
, and
Sun
,
D.-J.
, 2008, “
A General Formula of Degree of Freedom of Parallel Mechanisms
,”
Proceeding of the ASME 32nd Annual Mechanisms and Robotics Conference
, Paper No. DETC2008-49077.
32.
Yang
,
T. L.
,
Liu
,
A.-X.
,
Luo
,
Y.-F.
,
Shen
,
H.-P.
,
Hang
,
L.-B.
, and
Jin
,
Q.
,2009, “
A Systematical Approach for Structure Synthesis of Parallel Mechanisms Based on Position and Orientation Characteristics
,”
Proceeding of the ASME 33rd Annual Mechanisms and Robotics Conference
, Paper No. DETC2009-86106.
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