Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
• apa
• ieee
• modern-language-association-8th-edition
• vancouver
• Annat format
Fler format
Språk
• de-DE
• en-GB
• en-US
• fi-FI
• nn-NO
• nn-NB
• sv-SE
• Annat språk
Fler språk
Utmatningsformat
• html
• text
• asciidoc
• rtf
Material Impulse Response Estimation from Overlapping Ultrasound Echoes Using a Compressed Sensing Technique
Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.ORCID-id: 0000-0002-6216-6132
Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system. Rubico Vibration Analysis AB.
Rubico Vibration Analysis AB.
2017 (Engelska)Ingår i: IEEE International Ultrasonics Symposium, IUS, IEEE Computer Society, 2017, artikel-id 8092248Konferensbidrag, Muntlig presentation med publicerat abstract (Refereegranskat)
##### Abstract [en]

In ultrasound examination of thin multi-layered materials, the received signal is, in both through-transmission and pulse-echo configurations, a superposition of multiple reflections from inside the sample. If the layer thicknesses are small compared to the duration of the emitted ultrasound pulse, the received signal will be a sum of overlapping ultrasound pulses. In such scenarios, estimation of the layer thicknesses is challenging. Previous work has adopted model-based decomposition of the overlapping echoes, or various pulse compression or deconvolution schemes, in order to better reveal the arrival times of each individual echo.

##### Ort, förlag, år, upplaga, sidor
IEEE Computer Society, 2017. artikel-id 8092248
##### Serie
IEEE International Ultrasonics Symposium, ISSN 1948-5719, E-ISSN 1948-5727
Signalbehandling
Signalbehandling
##### Identifikatorer
Scopus ID: 2-s2.0-85039420470ISBN: 978-1-5386-3383-0 (digital)ISBN: 978-1-5386-3384-7 (tryckt)OAI: oai:DiVA.org:ltu-64966DiVA, id: diva2:1129763
##### Konferens
2017 IEEE International Ultrasonics Symposium (IUS), Washington D.C., 6-9 Sept. 2017
##### Ingår i avhandling
1. Blind Adaptive Extraction of Impulsive Signatures from Sound and Vibration Signals
Öppna denna publikation i ny flik eller fönster >>Blind Adaptive Extraction of Impulsive Signatures from Sound and Vibration Signals
2017 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
##### Abstract [en]

The two questions in science why" and how" are hereby answered in the context of statistical signal processing applied to vibration analysis and ultrasonic testing for fault detection and characterization in critical materials such as rolling bearings and thin layered media. Both materials are of interest in industrial processes. Therefore, assuring the best operating conditions on rolling bearings and product quality in thin layered materials is important.

The methods defended in this thesis are for retrieval of the impulsive signals arising from such equipments and materials, representing either faults or responses to an excitation. As the measurements collected via sensors usually consist of signals masked by some unknown systems and noise, retrieving the information-rich portion is often challenging. By exploiting the statistical characteristics due to their natural structure, a linear system is designed to recover the signals of interest in different scenarios. Suppressing the undesired components while enhancing the impulsive events by iteratively adapting a filter is the primary approach here. Signal recovery is accomplished by optimizing objectives (skewness and $\ell_1$-norm) quantifying the presumed characteristics, rising the question of objective surface topology and probability of ill convergence. To attack these, mathematical proofs, experimental evidences and comprehensive discussions are presented in the contributions each aiming to answer a specific question.

The aim in the theoretical study is to fill a gap in signal processing by providing analytical and numerical results especially on \emph{skewness} surface characteristics on a signal model (periodic impulses) build on harmonically related sinusoids. With understanding the inner workings and the conditions to suffice, the same approach is applied to different class of signals in ultrasonic testing, such as aperiodic finite energy signals (material impulse response) and a very short duration impulse as an excitation. A similar optimization approach aiming to enhance another attribute, \emph{sparseness}, is experimented numerically on the aforementioned signals as a case study. To summarize, two different objectives each quantifying a certain characteristic are optimized to recover signals carrying valuable information buried in noisy vibration and ultrasonic measurements.

Considering the fact that a research is qualified as successful if it creates more questions than it answers and lets ideas flourish creating scientific value, the presented work aims to achieve this in statistical signal processing. Analytical derivations assisted with experiments form the basis for observations, discussions and further questions to be studied and directed on similar phenomena arising from different sources in nature.

##### Ort, förlag, år, upplaga, sidor
Luleå tekniska universitet, 2017
##### Serie
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
##### Nationell ämneskategori
Elektroteknik och elektronik
Signalbehandling
##### Identifikatorer
urn:nbn:se:ltu:diva-64982 (URN)978-91-7583-933-2 (ISBN)978-91-7583-934-9 (ISBN)
##### Disputation
2017-10-18, A109, 10:15 (Engelska)

#### Open Access i DiVA

Fulltext saknas i DiVA

#### Övriga länkar

Förlagets fulltextScopus

#### Personposter BETA

Carlson, Johan E.

#### Sök vidare i DiVA

##### Av författaren/redaktören
Carlson, Johan E.
##### Av organisationen
Signaler och system
Signalbehandling

doi
isbn
urn-nbn

#### Altmetricpoäng

doi
isbn
urn-nbn
Totalt: 148 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
• apa
• ieee
• modern-language-association-8th-edition
• vancouver
• Annat format
Fler format
Språk
• de-DE
• en-GB
• en-US
• fi-FI
• nn-NO
• nn-NB
• sv-SE
• Annat språk
Fler språk
Utmatningsformat
• html
• text
• asciidoc
• rtf