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Carlson, J. E., Ovacikli, A. K. & Pääjärvi, P. (2017). Material Impulse Response Estimation from Overlapping Ultrasound Echoes Using a Compressed Sensing Technique. In: IEEE International Ultrasonics Symposium, IUS: . Paper presented at 2017 IEEE International Ultrasonics Symposium (IUS), Washington D.C., 6-9 Sept. 2017. IEEE Computer Society, Article ID 8091788.
Open this publication in new window or tab >>Material Impulse Response Estimation from Overlapping Ultrasound Echoes Using a Compressed Sensing Technique
2017 (English)In: IEEE International Ultrasonics Symposium, IUS, IEEE Computer Society, 2017, article id 8091788Conference paper, Published paper (Refereed)
Abstract [en]

When investigating thin materials with pulse echo ultrasound, multiple reflections (reverberations) from the layer(s) will overlap. It is therefore difficult to deduce information about speed of sound, thickness, density, etc. from the raw data. In order to extract this information, the overlapping pulses must be either decoupled or we must find some model of the material sample describing the wave propagation. It is, however, often reasonable to assume that the the number of reflections is small relative to the number of samples in the record signal of interest. In other words, the system describing the reverberations is sparse. In this paper we investigate, with simulations and with experiments on a 4.8 and 2.2 mm thick glass plate, respectively, how the framework of compressed sensing can be adopted in order to retrieve the impulse response of the material specimen

Place, publisher, year, edition, pages
IEEE Computer Society, 2017
Series
IEEE International Ultrasonics Symposium, ISSN 1948-5719, E-ISSN 1948-5727
Keywords
Glass, Ultrasonic imaging, Compressed sensing, Reverberation, Transducers, Shape, Ultrasonic variables measurement
National Category
Signal Processing
Research subject
Signal Processing
Identifiers
urn:nbn:se:ltu:diva-67246 (URN)10.1109/ULTSYM.2017.8091788 (DOI)000416948400102 ()2-s2.0-85039445752 (Scopus ID)978-1-5386-3383-0 (ISBN)978-1-5386-3384-7 (ISBN)
Conference
2017 IEEE International Ultrasonics Symposium (IUS), Washington D.C., 6-9 Sept. 2017
Available from: 2018-01-11 Created: 2018-01-11 Last updated: 2018-12-06Bibliographically approved
Carlson, J. E., Ovacikli, A. K. & Pääjärvi, P. (2017). Material Impulse Response Estimation from Overlapping Ultrasound Echoes Using a Compressed Sensing Technique. In: IEEE International Ultrasonics Symposium, IUS: . Paper presented at 2017 IEEE International Ultrasonics Symposium (IUS), Washington D.C., 6-9 Sept. 2017. IEEE Computer Society, Article ID 8092248.
Open this publication in new window or tab >>Material Impulse Response Estimation from Overlapping Ultrasound Echoes Using a Compressed Sensing Technique
2017 (English)In: IEEE International Ultrasonics Symposium, IUS, IEEE Computer Society, 2017, article id 8092248Conference paper, Oral presentation with published abstract (Refereed)
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.

Place, publisher, year, edition, pages
IEEE Computer Society, 2017
Series
IEEE International Ultrasonics Symposium, ISSN 1948-5719, E-ISSN 1948-5727
National Category
Signal Processing
Research subject
Signal Processing
Identifiers
urn:nbn:se:ltu:diva-64966 (URN)10.1109/ULTSYM.2017.8092248 (DOI)2-s2.0-85039420470 (Scopus ID)978-1-5386-3383-0 (ISBN)978-1-5386-3384-7 (ISBN)
Conference
2017 IEEE International Ultrasonics Symposium (IUS), Washington D.C., 6-9 Sept. 2017
Available from: 2017-08-07 Created: 2017-08-07 Last updated: 2018-12-06Bibliographically approved
Carlson, J., van de Beek, J. & Mohamad, M. (2017). Mbit/second Communication through a Rock Bolt Using Ultrasound. In: : . Paper presented at 2017 IEEE International Ultrasonics Symposium (IUS), Washington D.C., 6-9 Sept. 2017. Piscataway, NJ: IEEE, Article ID 8092454.
Open this publication in new window or tab >>Mbit/second Communication through a Rock Bolt Using Ultrasound
2017 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

In most industrial processes transfer of data and software from or to sensors is an essential part of the monitoring and control systems. Many of the older, wired communication systems have been or are being replaced with wireless alternatives. A number of challenges are associated with this replacement: Radio receivers are subject to interference from other radio sources. Similarly, radio transmitters may cause undesired interference into other equipment and environments. Compared to wired solutions, security becomes an issue as radio communication links are more vulnerable to eavesdropping than wired schemes. Radio communication with sensors and sensor platforms embedded deep inside large metal structures or fluid tanks may be difficult or even impossible. The objective of this work is to develop and evaluate a high data-rate communications scheme based on ultrasound, which can be used to transmit wirelessly through solid structures. An example will be given using a one-meter segment of a rock bolt.

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE, 2017
Series
IEEE International Ultrasonics Symposium, ISSN 1948-5719, E-ISSN 1948-5727
Keywords
Ultrasonic imaging, Rocks, Fasteners, Sensors, Radio communication, Interference, Channel estimation
National Category
Signal Processing Telecommunications
Research subject
Signal Processing
Identifiers
urn:nbn:se:ltu:diva-66541 (URN)10.1109/ULTSYM.2017.8092454 (DOI)2-s2.0-85039419149 (Scopus ID)978-1-5386-3383-0 (ISBN)
Conference
2017 IEEE International Ultrasonics Symposium (IUS), Washington D.C., 6-9 Sept. 2017
Available from: 2017-11-10 Created: 2017-11-10 Last updated: 2018-12-07Bibliographically approved
Carlson, J., van de Beek, J. & Mohamad, M. (2017). Mbit/second Communication through a Rock Bolt Using Ultrasound. In: IEEE International Ultrasonics Symposium, IUS: . Paper presented at 2017 IEEE International Ultrasonics Symposium (IUS), Washington D.C., 6-9 Sept. 2017. Piscataway, NJ: IEEE Computer Society, Article ID 8092474.
Open this publication in new window or tab >>Mbit/second Communication through a Rock Bolt Using Ultrasound
2017 (English)In: IEEE International Ultrasonics Symposium, IUS, Piscataway, NJ: IEEE Computer Society, 2017, article id 8092474Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a digital communication system based on Orthogonal Frequency Division Multiplexing (OFDM) and MHz-range ultrasound, for transmission of data through solid materials and liquids. The system is tested on experiments using a off-the-shelf ultrasound transducers with a center frequency of 3.5 MHz as transmitter and receiver, respectively. The propagation medium in the experiment was a 1 m long section of an epoxy coated steel rock bolt. The results show that data rates in excess of 1 Mbit/second is attainable, using readily available hardware and software.

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE Computer Society, 2017
Series
IEEE International Ultrasonics Symposium, ISSN 1948-5719, E-ISSN 1948-5727
National Category
Signal Processing Telecommunications
Research subject
Signal Processing
Identifiers
urn:nbn:se:ltu:diva-65477 (URN)10.1109/ULTSYM.2017.8092474 (DOI)000416948402010 ()978-1-5386-3383-0 (ISBN)978-1-5386-3384-7 (ISBN)
Conference
2017 IEEE International Ultrasonics Symposium (IUS), Washington D.C., 6-9 Sept. 2017
Available from: 2017-09-04 Created: 2017-09-04 Last updated: 2018-12-07Bibliographically approved
Sand, A., Stener, J., Toivakka, M., Carlson, J. & Pålsson, B. (2016). A Stokesian Dynamics Approach for Simulation of Magnetic Particle Suspensions (ed.). Paper presented at Computational Modelling '15 : 08/06/2015 - 10/06/2015. Minerals Engineering, 90(SI ), 70-76
Open this publication in new window or tab >>A Stokesian Dynamics Approach for Simulation of Magnetic Particle Suspensions
Show others...
2016 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 90, no SI , p. 70-76Article in journal (Refereed) Published
Abstract [en]

The dynamic behaviour of μm-scale ferromagnetic particles in suspension is of interest for various mineral beneficiation processes. It is, however, difficult to experimentally study such processes at the particle-level. In these instances it can be advantageous to resort to suitable particle simulation methods.Stokesian dynamics is a mesh-free numerical technique developed for suspensions of nm to mm size particles. The method inherently considers hydrodynamic interactions, but additional interaction models can be included depending on the system under investigation. We here present a Stokesian dynamics (SD) implementation, which allows for simulation of the motion of suspended magnetic particles in presence of an external magnetic field. The magnetic interaction model includes particle-field interactions as well as pairwise interactions between magnetised particles.Simulations are compared with experiments using a laboratory-scale flow cell. The method is shown to be realistic for studying ferromagnetic suspensions in mineral processing applications, and can be useful in understanding and predicting the efficiency of mineral separation processes.

National Category
Metallurgy and Metallic Materials Signal Processing
Research subject
Mineral Processing; Signal Processing
Identifiers
urn:nbn:se:ltu:diva-27464 (URN)10.1016/j.mineng.2015.10.015 (DOI)000375169200007 ()2-s2.0-84960865330 (Scopus ID)0eda3225-823b-4369-91a2-78b07835122b (Local ID)0eda3225-823b-4369-91a2-78b07835122b (Archive number)0eda3225-823b-4369-91a2-78b07835122b (OAI)
Conference
Computational Modelling '15 : 08/06/2015 - 10/06/2015
Note
Validerad; 2016; Nivå 1; 20151102 (andbra); Konferensartikel i tidskriftAvailable from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Ovacikli, K., Carlson, J. & Pääjärvi, P. (2016). Blind pulse compression through skewness maximization on overlapping echoes from thin layers. In: IEEE Ultrasonics Symposium 2016, Tours France, September 18-21, 2016: . Paper presented at IEEE Ultrasonics Symposium 2016, Tours France, September 18-21, 2016. Piscataway, NJ: IEEE conference proceedings, Article ID 7728571.
Open this publication in new window or tab >>Blind pulse compression through skewness maximization on overlapping echoes from thin layers
2016 (English)In: IEEE Ultrasonics Symposium 2016, Tours France, September 18-21, 2016, Piscataway, NJ: IEEE conference proceedings, 2016, article id 7728571Conference paper, Published paper (Refereed)
Abstract [en]

Pulse compression on overlapping echoes without knowledge of the pulse shape, transducer and propagation path impulse response is examined to provide valuable information about the sample structure in ultrasonic testing. A comparison against previous research is presented on two different levels of overlap severity with simulated signals. By exploiting the knowledge on the statistical characteristics of the signal of interest, an appropriate measure of merit, such as skewness, is maximized to promote impulsive occurrences to both extract the excitation signal and to enhance the impulse response of a material under test.

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE conference proceedings, 2016
Series
Proceedings - IEEE Ultrasonics Symposium, ISSN 1948-5719
Keywords
Dictionary Learning, Acoustic Emission
National Category
Signal Processing
Research subject
Signal Processing
Identifiers
urn:nbn:se:ltu:diva-61039 (URN)10.1109/ULTSYM.2016.7728571 (DOI)000387497400198 ()2-s2.0-84996489201 (Scopus ID)67766b7e-31af-44f5-b818-97f7fc13e9fc (Local ID)978-1-4673-9897-8 (ISBN)978-1-4673-9898-5 (ISBN)67766b7e-31af-44f5-b818-97f7fc13e9fc (Archive number)67766b7e-31af-44f5-b818-97f7fc13e9fc (OAI)
Conference
IEEE Ultrasonics Symposium 2016, Tours France, September 18-21, 2016
Available from: 2016-12-12 Created: 2016-12-12 Last updated: 2017-12-13Bibliographically approved
Stener, J., Carlson, J. E., Pålsson, B. & Sand, A. (2016). Direct measurement of internal material flow in a bench scale wet Low-Intensity Magnetic Separator (ed.). Paper presented at Physical Separation '15 : 11/06/2015 - 12/06/2015. Minerals Engineering, 91, 55-65
Open this publication in new window or tab >>Direct measurement of internal material flow in a bench scale wet Low-Intensity Magnetic Separator
2016 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 91, p. 55-65Article in journal (Refereed) Published
Abstract [en]

In this work an ultrasound-based measurement method is used formonitoring suspension velocity and build-up of magnetic material inside awet Low-Intensity Magnetic Separator, a process used e.g. inbeneficiation of magnetite ores. Today the only available option is tomonitor material transport between unit operations; i.e. flow rate,solids concentration, and particle size distribution of suspension flowin pipes are measured online using standard equipment.An Acoustic Backscatter System is fitted to the tank of a separator, andused to monitor the internal flow. A method called Ultrasonic VelocityProfiling is used to capture internal velocity profiles. Simultaneously,the backscatter signal intensity is used to get indications about localsolids concentration of the flow, and build-up of magnetic material. Themethods are evaluated in realistic conditions, where the effect ofvarying factors relevant to machine performance is investigated. Theincluded factors are; the slurry feed rate, the slurry solidsconcentration, the magnet assembly angle, and the drum rotational speed.The presented method gives useful information about the internal materialflow inside the separator. The velocity measurements capture the,sometimes complex, internal flow patterns, for example the presence andvelocity of a recirculating flow in the dewatering zone. Additionally,keeping a balanced material loading in the concentrate dewatering zone isimportant to separator performance. Using the signal backscatterintensity it is possible to qualitatively monitor this material loading.Generally these direct measurements can aid in improvements to machinedesign, process optimization, and process control.

National Category
Metallurgy and Metallic Materials Signal Processing
Research subject
Mineral Processing; Signal Processing
Identifiers
urn:nbn:se:ltu:diva-29949 (URN)10.1016/j.mineng.2015.10.021 (DOI)000375513500006 ()2-s2.0-84977914569 (Scopus ID)395c8b74-5c0d-42d1-9239-9141cede269c (Local ID)395c8b74-5c0d-42d1-9239-9141cede269c (Archive number)395c8b74-5c0d-42d1-9239-9141cede269c (OAI)
Conference
Physical Separation '15 : 11/06/2015 - 12/06/2015
Projects
Wet LlMS - Measurements and models
Note
Validerad; 2016; Nivå 1; 20151007 (janste); Konferensartikel i tidskriftAvailable from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Stener, J., Carlson, J., Sand, A. & Pålsson, B. (2016). Internal flow measurements in pilot scale wet low-intensity magnetic separation (ed.). International Journal of Mineral Processing, 155, 55-63
Open this publication in new window or tab >>Internal flow measurements in pilot scale wet low-intensity magnetic separation
2016 (English)In: International Journal of Mineral Processing, ISSN 0301-7516, E-ISSN 1879-3525, Vol. 155, p. 55-63Article in journal (Refereed) Published
Abstract [en]

In the mining industry, ferromagnetic particles (e.g. magnetite) are concentrated using wet low-intensity magnetic separation (LIMS). The performance is to a large extent controlled by the internal flow conditions in the separator. In previous work, it was shown how an ultrasound pulse-echo setup can be used to simultaneously measure particle velocity profiles and local solids concentration variations in laboratory conditions. In this paper, a real-world case is demonstrated where the system is installed on one of the wet LIMS at the LKAB R&D facilities in Malmberget, Sweden. For the pilot scale experiments a setup with two ultrasound transducers, mounted at the bottom of the separator tank, is used. The design of experiments method is used to study the effects of the feed solids concentration, drum rotational speed, position of the concentrate weir, and the magnet assembly angle on the measured flow patterns. The results show that it is possible to detect changes in the flow velocity patterns and the local solids concentration, as the operational conditions of the separator are varied. Of the factors studied, the drum rotational speed has the strongest influence on the overall flow velocity in the dewatering zone. Also, the presence of a recirculating flow transporting gangue particles away from the concentrate is confirmed. The factor with the strongest influence on this recirculating flow is also the drum rotational speed, together with the magnet assembly angle. Using this method it is possible to make high quality measurements of internal flow velocity profiles. It is also possible to monitor material build-up on the separator drum, and e.g. detect overload of magnetic material. The insights gained, and the methods developed, have generated new possibilities to control, optimise, and develop the wet LIMS process.

National Category
Metallurgy and Metallic Materials Signal Processing
Research subject
Mineral Processing; Signal Processing
Identifiers
urn:nbn:se:ltu:diva-8750 (URN)10.1016/j.minpro.2016.08.008 (DOI)000385472200006 ()2-s2.0-84983739058 (Scopus ID)749242bb-1c30-49e4-9d11-2910e9ad6cd7 (Local ID)749242bb-1c30-49e4-9d11-2910e9ad6cd7 (Archive number)749242bb-1c30-49e4-9d11-2910e9ad6cd7 (OAI)
Projects
Wet LlMS - Measurements and models
Note

Validerad; 2016; Nivå 2; 20160812 (janste)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Stener, J., Carlson, J., Sand, A. & Pålsson, B. (2016). Monitoring Mineral Slurry Flow using Pulse-Echo Ultrasound (ed.). Flow Measurement and Instrumentation, 50, 135-146
Open this publication in new window or tab >>Monitoring Mineral Slurry Flow using Pulse-Echo Ultrasound
2016 (English)In: Flow Measurement and Instrumentation, ISSN 0955-5986, E-ISSN 1873-6998, Vol. 50, p. 135-146Article in journal (Refereed) Published
Abstract [en]

Ultrasound based flow measurement methods have a large potential for the mining industry and its processing plants. Ultrasound travel through dense suspensions and is not affected by the magnetic fields sometimes present in this type of equipment.A cross-correlation based method is used for localized particle velocity measurements in one and two dimensions. Simultaneously, using the same data, information about local particle concentration is extracted from the power spectral density of the backscattered signal. Experiments are carried out both in simplified geometry and in full scale equipment in an iron ore pilot benefication plant.In the simple geometry it is possible to assess the precision of the methods by comparing the measurements to theory and numerical simulations. The results from the pilot plant experiments show that these methods can be applied to real world processes

National Category
Metallurgy and Metallic Materials Signal Processing
Research subject
Mineral Processing; Signal Processing
Identifiers
urn:nbn:se:ltu:diva-11762 (URN)10.1016/j.flowmeasinst.2016.06.022 (DOI)000383826800015 ()2-s2.0-84978027775 (Scopus ID)ac5e0544-9c34-42c3-b92f-16cc7bb885fe (Local ID)ac5e0544-9c34-42c3-b92f-16cc7bb885fe (Archive number)ac5e0544-9c34-42c3-b92f-16cc7bb885fe (OAI)
Note

Validerad; 2016; Nivå 2; 20160627 (johanc)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Jacobson, K., Carlson, J. E. & Lindblad, P. (2016). Non-Destructive Testing of Plastics and Composites in the Chemical Processing Industry. In: : . Paper presented at 19th World Conference on Non-Destructive Testing, Munich, 13-17 June 2016.
Open this publication in new window or tab >>Non-Destructive Testing of Plastics and Composites in the Chemical Processing Industry
2016 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Equipment and components made of plastics and composites are widely used in highly corrosive environments in the processing industry. Examples are the storage tanks, pumps and pipes for chemical transport and stacks in combustion plants. The demand for reliable nondestructive testing of plastic process equipment has increased significantly in recent years. Glass fiber reinforced plastics (GRP) is a common construction material for process equipment in the chemical industry. It can be used both as structural bearing in a dual laminate with a thermoplastic material as a corrosion barrier or as a solid GRP. In the latter case, the laminate is generally built up with a resin rich corrosion barrier (about 2.5 to 5 mm thick) with a low content of glass closest to the chemical. The glass fiber in this layer is usually a surface veil and chopped strand mats (CSM), i.e. it has no general fiber orientation. Outside this is the structural bearing layer with much higher glass content, usually wound fiber and / or woven fiber mats with a preferential fiber direction. The corrosion barrier is not load bearing and corrosion of this layer can be allowed. However, no corrosion can be permitted in the structural support layer. Because of this it is important to measure the thickness of the corrosion barrier for quality control but also to determine how far an attack has reached in the corrosion barrier. Today there is no non-destructive testing method that can answer this. Instead destructive sampling (often a drill core) must be made. This is difficult, expensive and sometimes impossible. There is thus a great interest in a method that, preferably at any time during operation, can provide answers to these questions. Due to the heterogeneity of the GRP material in terms of amount, type and direction of the fibers, conventional algorithm for ultrasound imaging will not work. One aim of our work is thus to develop new signal processing methods to handle this heterogeneity. In addition we are also looking at the possibility to use optical fibers and Fiber Bragg Grating (FBG) sensors for corrosion monitoring of GRP structures

National Category
Signal Processing Chemical Process Engineering Polymer Technologies
Research subject
Signal Processing
Identifiers
urn:nbn:se:ltu:diva-66210 (URN)
Conference
19th World Conference on Non-Destructive Testing, Munich, 13-17 June 2016
Available from: 2017-10-21 Created: 2017-10-21 Last updated: 2017-11-24Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-6216-6132

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