Title
Maximum likelihood defect localization in a pipe using guided acoustic waves.
Abstract
We discuss image formation using Maximum Likelihood (ML) for the localization of defects in pipes. We make use of guided waves (similar to Lamb waves in plates). We utilize a data-driven approach based on a priori measurements of the Green's function for a pre-defined number of grid points to overcome the complex modeling problem of dispersive, multi-modal guided waves in this environment. We then compute the ML estimate of reflectivity at each pixel given some received signal vector. We compare this approach to both backprojection and MUSIC imaging for the same set of reference and test data. We show that, for synthesized defects in a lab setting, all three approaches successfully image the defects. However, in situ measurements taken on an active hot water return pipe show that only Maximum Likelihood imaging is successful in a realistic operational environment.
Year
DOI
Venue
2012
10.1109/ACSSC.2012.6489360
ACSCC
Keywords
DocType
ISSN
Green's function methods,image classification,maximum likelihood estimation,mechanical engineering computing,pipes,reliability,surface acoustic waves,ultrasonic dispersion,Green's function,Lamb wave,ML estimation,MUSIC imaging,backprojection,complex modeling problem,data-driven approach,dispersive multimodal guided acoustic wave,hot water return pipe,image formation,maximum likelihood defect localization,maximum likelihood imaging,pre-defined grid point number,received signal vector,ultrasonic guided wave,Defect Localization,Maximum Likelihood,Non-Destructive Evaluation
Conference
1058-6393
Citations 
PageRank 
References 
0
0.34
0
Authors
5
Name
Order
Citations
PageRank
Nicholas O'Donoughue1445.02
Joel B. Harley2123.11
Chang Liu300.34
José M. F. Moura45137426.14
Irving Oppenheim5253.33