Direction of Arrival Estimation of Lamb Waves Using Circular Arrays
2011 (English)In: Structural Health Monitoring, ISSN 1475-9217, E-ISSN 1741-3168, Vol. 10, no 5, 467-480 p.Article in journal (Refereed) Published
Uniform circular arrays (UCAs) with 360 degrees azimuthal coverage are very useful for structural health monitoring (SHM) of large planar structures. Difficulties encountered when working with Lamb waves include their dispersive and multi-modal nature. In this paper three different methods for estimating the direction-of-arrival (DOA) of incoming Lamb waves are compared and verified using simulated and experimental data. The previously proposed phase-mode excitation based beamformer is compared with two high-resolution spectral estimation techniques, the Capon method and the multiple signal classification method (MUSIC). Design consideration and guidelines for UCAs are presented. To experimentally evaluate the performance of the considered DOA methods a prototype array consisting of 16 separate pinducers arranged in a ring was constructed. The array was provided with an analog multiplexer that enabled recording signals received by the individual elements using a digital oscilloscope. The array was used for the reception of ultrasonic pulses sent by broadband piezoelectric transmitters and propagating in an aluminum plate. A selection of simulation and experimental results is presented showing the superior performance of the Capon beamformer.
Place, publisher, year, edition, pages
2011. Vol. 10, no 5, 467-480 p.
array signal processing, adaptive beamforming, guided waves, dispersive waves, multi-modal waves
Engineering and Technology
Research subject Electrical Engineering with specialization in Signal Processing
IdentifiersURN: urn:nbn:se:uu:diva-122107DOI: 10.1177/1475921710379512ISI: 000294287000002OAI: oai:DiVA.org:uu-122107DiVA: diva2:309347