Optimization of Test Parameters for Magneto-Optic Imaging Using Taguchi's Parameter Design and Response-Model Approach

Abstract

Magneto-optic/eddy current imaging (MOI) is becoming widely used for aging aircraft inspection for cracks and corrosion. However, many test parameters affect the accept/reject decision about a test sample and hence the overall performance of MOI system. The optimization of the parameters is extremely crucial in enhancing the performance of MOI system. This article uses the Taguchi method to change parameter values simultaneously to search for the optimum set of test parameters for maximizing system performance for a given sample geometry and critical crack. It is also important at the same time the system performance be unaffected by variations in parameters. Efficiency of Taguchi's partial factorial design is obvious. The optimum set of parameters is found by means of analyses of main effects. Analysis of variance identifies those parameters that need to be controlled carefully. A response-model approach is utilized as a complement to the Taguchi method.

Keywords:

• finite element method
• magneto-optic imaging
• response-model approach
• robust design
• Taguchi method

ACKNOWLEDGMENTS

This work is supported by the Federal Aviation Administration and performed at Michigan State University as part of the Center for Aviation Systems Reliability program.

Notes

μ: mean response; σ: standard deviation; (S/N)₁ = 10log₁₀(μ²/σ²); (S/N)₂ = 10log₁₀(MSD).

f: DOF; S: sum of squares; V: variance; P: percent contribution.

Gerald Fitzpatrick, PRI Research and Development Corporation, Torrance, CA also contributed to this research.