Singularity Issues in Fixture Fault Diagnosis for Multi-Station Assembly Processes
Author:
Ding Yu1, Gupta Abhishek1, Apley Daniel W.2
Affiliation:
1. Department of Industrial Engineering, Texas A&M University, TAMU 3131, College Station, TX 77843-3131 2. Department of Industrial Engineering and Management Sciences, Northwestern University, Evanston, IL 60208-3119
Abstract
This paper presents a method of diagnosing variance components of process error sources in singular manufacturing systems. The singularity problem is studied and the cause examined in the context of fixture error diagnosis in multi-station assembly processes. The singularity problem results in nondiagnosable fixture errors when standard least-squares (LS) estimation methods are used. This paper suggests a reformulation of the original error propagation model into a covariance relation. The LS criterion is then applied directly to the sample covariance matrix to estimate the variance components. Diagnosability conditions for this variance LS estimator are derived, and it is demonstrated that certain singular systems that are not diagnosable using traditional LS methods become diagnosable with the variance LS estimator. Modified versions that improve the accuracy of the variance LS estimator are also presented. The various procedures are thoroughly contrasted, in terms of accuracy and diagnosability. The results are illustrated with examples from panel assembly, although the application of the approach and the conclusions extend to more general discrete-part manufacturing processes where fixtures are used to ensure dimensional accuracy of the final product.
Publisher
ASME International
Subject
Industrial and Manufacturing Engineering,Computer Science Applications,Mechanical Engineering,Control and Systems Engineering
Reference27 articles.
1. Shalon, D., Gossard, D., Ulrich, K., and Fitzpatrick, D., 1992, “Representing Geometric Variations in Complex Structural Assemblies on CAD Systems,” Proceedings of the 19th Annual ASME Advances in Design Automation Conference, DE-Vol. 44-2, pp. 121–132. 2. Ceglarek, D., and Shi, J., 1995, “Dimensional Variation Reduction for Automotive Body Assembly,” Manufacturing Review, 8, pp. 139–154. 3. Cunningham, T. W., Mantripragada, R., Lee, D. J., Thornton, A. C., and Whitney D. E., 1996, “Definition, Analysis, and Planning of a Flexible Assembly Process,” Proceedings of the 1996 Japan/USA Symposium on Flexible Automation, Vol. 2, pp. 767–778. 4. Ceglarek, D., and Shi, J., 1996, “Fixture Failure Diagnosis for the Autobody Assembly Using Pattern Recognition,” ASME J. Ind., 118, pp. 55–66. 5. Apley, D. W., and Shi, J., 1998, “Diagnosis of Multiple Fixture Faults in Panel Assembly,” ASME J. Manuf. Sci. Eng., 120, pp. 793–801.
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