Mechanical means of positioning are frequently used in mechanical assembly processes. However, very little attention has been paid to the proper design and selection of mechanical alignment systems (MAS) for assembly processes. In this paper, we study the performance of different MAS in terms of assembly accuracy in the presence of the form error, surface waviness and surface roughness of the references surfaces. In particular, simulation models are used to investigate how the datum pin configuration, datum pin location and datum geometry of the MAS would affect the assembly accuracy in the presence of surface errors of the workpieces. Our investigation can provide insight into how to design MAS for optimum performance for assembly accuracy. Our analysis shows that over an order of magnitude of difference in assembly accuracy can exist between using properly designed MAS and poorly design MAS.

1.
Xie, C., Guo, Z., and Chen, X., 1994, “A New Approach to Improvement Assembly Accuracy on Robot Automatic Assembly Line,” Procs 2nd Asian Conf on Robotics and Its Applications, Int. Acad. Publishers, pp. 121–125.
2.
Xie, C., Tang, X., Shao, M., and Zheng, J., 1997, “Accuracy Analysis and Modeling of Robot Flexible Assembly Process,” Procs 3rd ACRA, 3rd Asian Conf on Robotics and its Applications, Japan Robot Assoc., pp. 109–113.
3.
Pugh
,
G. A.
, 1992, “Selective Assembly with Components of Dissimilar Variance,” Computers and Industrial Engineering, 23(1–4), pp. 487–491.
4.
Park
,
Y. K.
, and
Cho
,
H. S.
,
1993
, “
A Fuzzy Rule-based Assembly Algorithm for Precision Parts Mating
,”
Mechatronics
,
3
(
4
), pp.
433
450
.
5.
Ceglarek
,
D.
,
Shi
,
J.
, and
Wu
,
S. M.
,
1994
, “
A Knowledge-Based Diagnostic Approach for the Launch of the Auto-body Assembly Process
,”
ASME J. Eng. Ind.
,
116
(
4
), pp.
491
499
.
6.
Zhang
,
Z.
, and
Fang
,
X. D.
,
1996
, “
Fit Capability Indices and Their Application
,”
Int. J. Prod. Res.
34
(
11
), pp.
3079
3094
.
7.
Kim
,
W. S.
, and
Cho
,
H. S.
,
1998
, “
A Novel Omnidirectional Image Sensing System for Assembling Parts with Arbitrary Cross-sectional Shapes
,”
IEEE/ASME Trans. Mechatron.
,
3
(
4
), pp.
275
292
.
8.
Ceglarek
,
D.
, and
Shi
,
J.
,
1996
, “
Fixture Failure Diagnostic for Autobody Assembly Using Pattern Recognition
,”
ASME J. Eng. Ind.
,
118
(
1
), pp.
55
65
.
9.
Asada
,
H.
, and
By
,
A.
,
1985
, “
Kinematic Analysis of Workpart Fixyuring for Flexible Assembly with Automatically Reconfigurable Fixtures
,”
IEEE J.Rob. Autom.
,
RA-1
(
2
), pp.
86
94
.
10.
Weill, R., Darel, I., and Laloum, M., 1991, “The Influence of Fixture Positioning Errors on Geometric Accuracy of Mechanical Parts,” Proceedings of CIRP Conference on PE & MS, pp. 215–225.
11.
Cai
,
W.
,
Hu
,
S. J.
, and
Yuan
,
J. X.
,
1997
, “
A Variational Method of Robust Fixture Configuration Design for 3-D Workpieces
,”
ASME J. Manuf. Sci. Eng.
,
119
, pp.
593
601
.
12.
Rong
,
Y.
, and
Bai
,
Y.
,
1996
, “
Machining Accuracy Analysis for Computer-aided Fixture Design Verification
,”
ASME J. Manuf. Sci. Eng.
,
118
, pp.
289
299
.
13.
Shawki
,
G. S. A.
, and
Abdel-Alal
,
1965
, “
Rigidity Consideration in Fixture Design-Contact Rigidity at Locating Elements
,”
Int. J. Mach. Tool Des. Res.
,
6
, pp.
31
43
.
14.
Shawki
,
G. S. A.
, and
Abdel-Aal
,
1965
, “
Rigidity Consideration in Fixture Design-Contact Rigidity of Clamping Elements
,”
Int. J. Mach. Tool Des. Res.
,
6
, pp.
207
220
.
15.
Shawki
,
G. S. A.
, and
Abel-Aal
,
1965
, “
Effect of Fixture Rigidity and Wear on Dimensional Accuracy
,”
Int. J. Mach. Tool Des. Res.
,
5
, pp.
183
202
.
16.
Hockenberger
,
M. J.
, and
DeMeter
,
E. C.
, 1995, “The Effect of Machining Fixture Design Parameters on Workpiece Displacement,” ASME Journal of Manufacturing Review, 8(1), pp. 22–32.
17.
DeMeter
,
E. C.
,
1995
, “
Min-max Load Model for Optimizing Machining Fixture Performance
,”
ASME J. Eng. Ind.
,
117
, pp.
186
193
.
18.
Cogun
,
C.
,
1992
, “
The Importance of the Application Sequence of Clamping Forces on Workpiece Accuracy
,”
ASME J. Eng. Ind.
,
114
, pp.
539
543
.
19.
Choudhuri
,
S. A.
, and
DeMeter
,
E. C.
,
1999
, “
Tolerance Analysis of Machining Fixture Locators
,”
ASME J. Manuf. Sci. Eng.
,
121
, pp.
273
281
.
20.
Hoffman, E. G., 1991, Jig and Fixture Design, 3rd ed., Delmar, NY.
21.
Ackerson
,
D. S.
, and
Harry
,
D. R.
,
1985
, “
Theory, Experimental Results, and Recommended Standards Regarding the Static Positioning and Orientation Precision of Industrial Robots
,”
Robotics and CIM
,
2
(
3/4
), pp.
247
259
.
22.
Lau
,
W. S.
, and
Ng
,
K. L.
,
1992
, “
Experimental and Statistical determination of the static position repeatability and a recommended specification for a SCARA robot
,”
Computer-Integrated Manufacturing
,
9
(
3
), pp.
247
253
.
23.
Lee
,
N. K. S.
,
Chen
,
J. Y.
, and
Joneja
,
A.
,
2001
, “
Effects of Surface Roughness on Multi-Station Mechanical Alignment Process
,”
ASME J. Manuf. Sci. Eng.
,
123
, pp.
433
444
.
24.
Fung
,
A. K.
, and
Chen
,
M. F.
,
1985
, “
Numerical Simulation of Scattering from Simple and Composite Random Surfaces
,”
J. Opt. Soc. Am. A
,
2
(
12
), pp.
2274
2284
.
25.
Yisok, O. H., 1997, “Precise Estimation of Surface Roughness Parameters from Field-measured Ground Truth,” IEEM, IGARSS’97, 1997 International Geoscience and Remote Sensing Symposium, Remote Sensing-A Scientific Vision for Sustainable Development (Cat. No. 97CH36042), IEEE, Vol. 2, pp. 708–710.
26.
Whitehouse
,
D. J.
, and
Archard
,
J. F.
,
1970
, “
The Properties of Random Surfaces of Significance in Their Contact
,”
Proc. R. Soc. London, Ser. A
,
316
(
1524
), pp.
97
121
.
You do not currently have access to this content.