In this paper, the author proposes a new method to design SCARA robots for higher repeatability. First, the author outlines various procedures used in optimal robot design and then points out among the various performance indices those related to repeatability. The author adds some new criteria issued from the stochastic ellipsoid theory. Another innovative part of the paper is to take into account a task-oriented strategy during the design stage, meaning the possibility of adapting task orientation and location in the robot workspace. These concepts are applied to SCARA optimal design. The method described here consists of considering simultaneously robot geometry and joint repeatability, keeping both the reach and the total cost of the sensors constant. It results in an optimization problem with adimensional ratios, which then allows easy comparisons with existing SCARA. The results are surprising and give some clues to answer the underlying question: Are industrial SCARA designed for high repeatability?

1.
Burisch
,
A.
,
Raatz
,
A.
, and
Hesselbach
,
J.
, 2010, “
Challenges of Precision Assembly With a Miniaturized Robot
,”
Precision Assembly Technologies and Systems
(
IFIP Advances in Information and Communication Technology
),
S.
Ratchev
, ed.,
Springer
,
Boston, MA
, Vol.
315
, pp.
227
234
.
2.
Das
,
A. N.
, 2009, “
Automated 3D Microassembly With Precision Adjusted Hybrid Supervisory Controller
,” Ph.D. thesis, University of Texas at Arlington, Arlington, TX.
3.
Briot
,
S.
, and
Bonev
,
I. A.
, 2009, “
Pantopteron: A New Fully Decoupled 3DOF Translational Parallel Robot for Pick-and-Place Applications
,”
ASME J. Mech. Rob.
1942-4302,
1
(
2
), p.
021001
.
4.
Nzue
,
R. -M.
,
Brethé
,
J. -F.
,
Vasselin
,
E.
, and
Lefebvre
,
D.
, 2010, “
Comparative Analysis of the Repeatability Performance of a Serial and Parallel Robot
,”
IROS
, pp.
63
68
.
5.
Salisbury
,
J. K.
, and
Craig
,
J. J.
, 1982, “
Articulated Hands: Force Control and Kinematic Issues
,”
Int. J. Robot. Res.
0278-3649,
1
(
1
), pp.
4
17
.
6.
Kircanski
,
M. V.
, and
Boric
,
M. Dj.
, 1993, “
Symbolic Singular Value Decomposition for a Puma Robot and Its Application to a Robot Operation Near Singularities
,”
Int. J. Robot. Res.
0278-3649,
12
(
5
), pp.
460
472
.
7.
Gosselin
,
C.
, 1992, “
The Optimal Design of Robotic Manipulators Using Dexterity Indices
,”
Rob. Auton. Syst.
0921-8890,
9
(
4
), pp.
213
226
.
8.
Gosselin
,
C.
, and
Angeles
,
J.
, 1991, “
A Global Performance Index for the Kinematic Optimisation of Robotic Manipulators
,”
ASME J. Mech. Des.
0161-8458,
113
(
3
), pp.
220
226
.
9.
Stocco
,
L.
,
Salcudean
,
S. E.
, and
Sassini
,
F.
, 1998, “
Fast Constrained Global Minimax Optimization of Robot Parameters
,”
Robotica
0263-5747,
16
, pp.
595
605
.
10.
Merlet
,
J. -P.
, 2006, “
Jacobian, Manipulability, Condition Number and Accuracy of Parallel Robots
,”
ASME J. Mech. Des.
0161-8458,
128
(
1
), pp.
199
206
.
11.
Ma
,
O.
, and
Angeles
,
J.
, 1991, “
Optimum Architecture Design of Platform Manipulator
,”
ICAR
, pp.
1131
1135
.
12.
Khan
,
W.
, and
Angeles
,
J.
, 2006, “
The Kinetostatic Optimisation of Robotic Manipulators: The Inverse and the Direct Problems
,”
ASME J. Mech. Des.
0161-8458,
128
, pp.
168
178
.
13.
Asada
,
H.
, 1983, “
A Geometrical Representation of Manipulator Dynamics and Its Application to Arm Design
,”
ASME J. Dyn. Syst., Meas., Control
0022-0434,
105
(
3
), pp.
131
135
.
14.
Yoshikawa
,
T.
, 1985, “
Manipulability of Robotics Mechanisms
,”
Int. J. Robot. Res.
0278-3649,
4
(
2
), pp.
3
9
.
15.
Graettinger
,
T. J.
, and
Krogh
,
B. H.
, 1988, “
The Acceleration Radius: A Global Performance Measure for Robotic Manipulators
,”
IEEE J. Rob. Autom.
0882-4967,
4
(
1
), pp.
60
69
.
16.
Griffis
,
M.
, and
Duffy
,
J.
, 1993, “
Global Stiffness Modeling of a Class of Simple Compliant Couplings
,”
Mech. Mach. Theory
0094-114X,
28
, pp.
207
224
.
17.
Howard
,
S.
, and
Zefran
,
M.
, 1998, “
On the 6×6 Cartesian Stiffness Matrix for Three-Dimensional Motions
,”
Mech. Mach. Theory
0094-114X,
33
, pp.
389
408
.
18.
Angeles
,
J.
, and
Park
,
F.
, 2008, “
Performance Evaluation and Design Criteria
,”
Springer Handbook of Robotics
,
Springer
,
New York
, Chap. 10, p.
235
.
19.
Chu
,
J.
, and
Sun
,
J.
, 2010, “
A New Approach to Dimension Synthesis of Spatial Four-Bar Linkage Through Numerical Atlas Method
,”
ASME J. Mech. Rob.
1942-4302,
2
(
4
), p.
041004
.
20.
ISO
, 1998, “
Manipulating Industrial Robots—Performance Criteria and Related Test Methods
,” ISO9283.
21.
ANSI
, 1990, “
American National Standard for Industrial Robots and Robot Systems—Point-to-Point and Static Performance Characteristics—Evaluation
,” R15.05-1-1990.
22.
Corbel
,
D.
,
Company
,
O.
,
Krut
,
S.
, and
Pierrot
,
F.
, 2010, “
Enhancing PKM Accuracy by Separating Actuation and Measurement: A 3DOF Case Study
,”
ASME J. Mech. Rob.
1942-4302,
2
(
3
), p.
031008
.
23.
Briot
,
S.
, and
Bonev
,
I. A.
, 2007, “
Are Parallel Robots More Accurate Than Serial Robots?
,”
Trans. Can. Soc. Mech. Eng.
0315-8977,
31
(
4
), pp.
445
456
.
24.
Briot
,
S.
, and
Bonev
,
I. A.
, 2010, “
Accuracy Analysis of 3T1R Fully-Parallel Robots
,”
Mech. Mach. Theory
0094-114X,
45
(
5
), pp.
695
706
.
25.
Ramsli
,
E.
, 1991, “
Probability Distribution of Repeatability of Industrial Robots
,”
Int. J. Robot. Res.
0278-3649,
10
, pp.
276
283
.
26.
Edan
,
Y.
,
Friedman
,
L.
,
Mehrez
,
A.
, and
Slutski
,
L.
, 1998, “
A Three-Dimensional Statistical Framework for Performance Measurement of Robotic Systems
,”
Rob. Comput.-Integr. Manufact.
0736-5845,
14
, pp.
307
315
.
27.
Riemer
,
R.
, and
Edan
,
Y.
, 2000, “
Evaluation of Influence of Target Location on Robot Repeatability
,”
Robotica
0263-5747,
18
, pp.
443
449
.
28.
Offodile
,
O. F.
, and
Ugwu
,
K.
, 1991, “
Evaluating the Effect of Speed and Payload on Robot Repeatability
,”
Rob. Comput.-Integr. Manufact.
0736-5845,
8
, pp.
27
33
.
29.
Brethé
,
J. -F.
,
Vasselin
,
E.
,
Lefebvre
,
D.
, and
Dakyo
,
B.
, 2005,
ICRA
,
IEEE
,
New York
, pp.
4339
4344
.
30.
Brethé
,
J. -F.
, and
Dakyo
,
B.
, 2002, “
A Stochastic Ellipsoid Approach to Repeatability Modelisation of Industrial Robots
,”
IROS
, pp.
1608
1613
.
31.
Brethé
,
J. -F.
,
Vasselin
,
E.
,
Lefebvre
,
D.
, and
Dakyo
,
B.
, 2006, “
Modelling of Repeatability Phenomena Using the Stochastic Ellipsoid Approach
,”
Robotica
0263-5747,
24
(
04
), pp.
477
490
.
32.
Tong
,
Y. L.
, 1988,
The Multivariate Normal Distribution
,
Springer-Verlag
,
Berlin
.
33.
Brethé
,
J. -F.
, 2010, “
Intrinsic Repeatability: A New Index for Repeatability Characterization
,”
ICRA
, pp.
3849
3854
.
34.
Wolf
,
A.
, and
Glozman
,
D.
, 2011, “
Singularity Analysis of Large Workspace 3RRRS Parallel Mechanism Using Line Geometry and Linear Complex Approximation
,”
ASME J. Mech. Rob.
1942-4302,
3
(
1
), p.
011004
.
35.
Hubert
,
J.
, and
Merlet
,
J.
, 2009, “
Static of Parallel Manipulators and Closeness to Singularity
,”
ASME J. Mech. Rob.
1942-4302,
1
(
1
), p.
011011
.
36.
Jiang
,
Q.
, and
Gosselin
,
C. M.
, 2010, “
Effects of Orientation Angles on the Singularity-Free Workspace and Orientation Optimization of the Gough–Stewart Platform
,”
ASME J. Mech. Rob.
1942-4302,
2
(
1
), p.
011001
.
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