Ändra sökning
Avgränsa sökresultatet
1234567 101 - 150 av 1000
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • 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
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 101.
    Borg, Johan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Johansson, Jonny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Delay insensitive signal-injection calibration for large antenna arrays using passive hierarchical networks2017Ingår i: IEEE Transactions on Antennas and Propagation, ISSN 0018-926X, E-ISSN 1558-2221, Vol. 65, nr 1, s. 190-195, artikel-id 7747455Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Efficient beamforming of phased-array antennas requires that the phase delay of each channel is accurately known. One technique for achieving this is to distribute a calibration or local-oscillator reference signal through a delay-insensitive signal distribution network. In this paper, we propose using passive hierarchical signal distribution networks to distribute such signals, a method that scales significantly better with the size of the array than existing signal distribution methods. We analyze the impact of impedance variations within the network on the phase accuracy and propose a calibration front-end architecture. This front end also enables the return loss and coupling between antennas to be monitored for diagnostic purposes. We present an implementation of this front end that was applied to a small prototype antenna array, and show that this implementation exhibited low sensitivity to delays within the calibration network, reduced the temperature-dependent phase error of the front ends substantially, and can be used for performing antenna return-loss measurements

  • 102.
    Borg, Johan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Johansson, Jonny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Evaluation of a surface-channel CCD manufactured in a pinned active-pixel-sensor CMOS process2011Ingår i: IEEE Transactions on Electron Devices, ISSN 0018-9383, E-ISSN 1557-9646, Vol. 58, nr 8, s. 2660-2664Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents measurements on a surfacechannel CCD with gates implemented using single-layer polysilicongates. The device was manufactured in a 0.18 μm PINNEDphoto diode CMOS process commercially available from UMC.The CCD was built with a field-plate covering all gates as wellas the space between them, which allows the potential in the gapbetween non-overlapping gates to be manipulated.We present charge transfer efficiency measurements performedat clock frequencies of 1 MHz and 5 MHz, at multiplebackground packet sizes, and field-plate voltages. We furtherpropose and apply a method for separating CTI in four-phaseCCDs due to trapping from the inefficiency stemming from otherphenomena.The measurements show a single stage CTI ranging from 1.7×10−4 with a moderate background charge and substantial fieldplatevoltage, to 0.007 at zero field-plate voltage and the highestbackground charge tested. The CTI can be reduced significantly(more than a factor of 10 in some cases) by applying a significantnegative voltage at the field-plate. This, and the fact that only aminor part of the CTI can be attributed to trapping, indicatesthat the performance of the device is limited by the presence ofpotential hollows in the gaps between the gates.

  • 103.
    Borg, Johan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Johansson, Jonny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Optimization of the design of an integrated ultrasonic preamplifier2008Ingår i: Proceedings of the International Congress on Ultrasonics: Vienna, April 9-13, 2007, International Congress on Ultrasonics , 2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    Traditionally BJT or BiCMOS amplifiers have been used to achieve equivalent input noise densities of 1 nV√Hz or less, as desirable in some ultrasonic applications. Due to an increasing demand on increased integration it can be necessary to implement the amplifier in a CMOS process. As part of this design process we applied the particle swarm optimization to the problem of optimizing an amplifier specifically for operation in the 2-4 MHz frequency band. We present measurements on the manufactured circuit with performance comparable to the best available BJT-based amplifiers available today.

  • 104.
    Borg, Johan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Johansson, Jonny
    van Deventer, Jan
    Delsing, Jerker
    Reciprocal operation of ultrasonic transducers: experimental results2006Ingår i: Proceedings: 2006 IEEE Ultrasonics Symposium : Vancouver, Canada, 3 - 6 October 2006, Piscataway, NJ: IEEE Communications Society, 2006, s. 1013-1016Konferensbidrag (Refereegranskat)
    Abstract [en]

    Ultrasonic transit-time flow-meters estimate fluid or gas flows from the difference in times of flight of upstream and downstream acoustic pulses. However, any delay differences arising from sources other than the flow to be measured will cause a troublesome "zero flow" offset error.In theory, the transducers used in the measurement system should not influence the zero flow error, as electroacoustic systems based on piezoelectric transducers have been shown to be reciprocal (when the media is stationary). However, care is required when designing the electrical interfaces for the piezoelectric transducers, if reciprocity in the system is to be utilized.This work presents technique and measurements that apply reciprocity to an ultrasonic transit-time flow-meter. Specialized electrical transducer interfaces with options to drive the transducers from either low or high impedance sources were used. Combined with a high-impedance receive mode these options made it possible to change the conditions for reciprocity in the system.We show reduced delay difference in 9 cases out of 10 when trying to utilize the reciprocal property compared to when we disregard it in favor for larger excitation energy. The delay improvements were accompanied by reduced differences between the center frequencies of the signals from the two paths.

  • 105.
    Borowski, Holly
    et al.
    University of Colorado, Boulder.
    Isoz, Oscar
    Luleå tekniska universitet, Institutionen för system- och rymdteknik.
    Lo, Sherman
    Stanford GPS Laboratory.
    Eklöf, Fredrik
    FOI.
    Akos, Dennis
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Detecting false signals with automatic gain control2012Ingår i: GPS World, ISSN 1048-5104, Vol. 23, nr 4, s. 38-43Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A component of most GPS receiver front-ends, the automatic gain control (AGC) can flag potential jamming and spoofing attacks. The detection method is simple to implement and accessible to most GPS receivers. It may be used alone or as a complement other anti-spoofing architectures. This article presents results from a baseline AGC characterization, develos a simple spoofing detection method, and demonstrate the results of that method on receiver data gathered in the presence of a live spoofing attack.

  • 106.
    Brodnik, Andrej
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Karlsson, Johan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Munro, Ian
    Faculty of Education, University of Primorska.
    Nilsson, Andreas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    An O(1) solution to the prefix sum problem on a specialized memory architecture2006Ingår i: PFourth IFIP International Conference on Theoretical Computer Science - TCS 2006: IFIP 19th World Computer Congress, TC-1, Foundations of Computer Science, August 23-24, 2006, Santiago, Chile / [ed] Gonzalo Navarro; Leopoldo Bertossi; Yoshiharu Kohayakawa, New York: Encyclopedia of Global Archaeology/Springer Verlag, 2006, s. 103-114Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper we study the Prefix Sum problem introduced by Fredman. We show that it is possible to perform both update and retrieval in O(1) time simultaneously under a memory model in which individual bits may be shared by several words. We also show that two variants (generalizations) of the problem can be solved optimally in Θ(lgN) time under the comparison based model of computation.

  • 107. Brodnik, Andrej
    et al.
    Nilsson, Andreas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    A static data structure for discrete advance bandwidth reservations on the Internet2003Ingår i: Proceedings of Swedish National Computer Networking Workshop: SNCNW 2003, Stockholm, 2003Konferensbidrag (Refereegranskat)
  • 108. Brodnik, Andrej
    et al.
    Nilsson, Andreas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    An efficient data structure for advance bandwidth reservations on the Internet2002Ingår i: Proceedings of CSEE 2002: Second Annual Conference on Computer Science and Electrical Engineering. The third Annual Symposium on Computer Science and Electrical Engineering, 2002Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this contribution we present a problem of resource reservation during some time. We show that the problem has a lower bound of Ω (log n) per operation on average and also give a matching upper bound algorithm.

  • 109. Brodnik, Andrej
    et al.
    Nilsson, Andreas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Data structure for a time-based bandwidth reservations problem2003Rapport (Övrigt vetenskapligt)
    Abstract [en]

    We discuss a problem of handling resource reservations. The resource can be reserved for some time, it can be freed or it can be queried what is the largest amount of reserved resource during a time interval. We show that the problem has a lower bound of $\Omega(\log n)$ per operation on average and we give a matching upper bound algorithm. Our solution also solves a dynamic version of the related problems of a prefix sum and a partial sum.

  • 110. Brodnik, Andrej
    et al.
    Nilsson, Andreas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Static data structure for discrete advance bandwidth reservations on the internet2003Rapport (Övrigt vetenskapligt)
    Abstract [en]

    In this paper we present a discrete data structure for reservations of limited resources. A reservation is defined as a tuple consisting of the time interval of when the resource should be reserved, $I_R$, and the amount of the resource that is reserved, $B_R$, formally $R=\{I_R,B_R\}$. The data structure is similar to a segment tree. The maximum spanning interval of the data structure is fixed and defined in advance. The granularity and thereby the size of the intervals of the leaves is also defined in advance. The data structure is built only once. Neither nodes nor leaves are ever inserted, deleted or moved. Hence, the running time of the operations does not depend on the number of reservations previously made. The running time does not depend on the size of the interval of the reservation either. Let $n$ be the number of leaves in the data structure. In the worst case, the number of touched (i.e. traversed) nodes is in any operation $O(\log n)$, hence the running time of any operation is also $O(\log n)$.

  • 111. Bucht, Thore
    et al.
    Kjellmert, Bo
    Löfqvist, Torbjörn
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Experimentell metodik1995 (uppl. 5)Bok (Övrig (populärvetenskap, debatt, mm))
  • 112.
    Cabrerizo, Ana Belén
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Telemedicin enabled mobile pulse and blood pressure sensor2000Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The last course, in the MSc in Electrical Engineering - Industrial Electronics, at Luleå University of Technology, is a project course. This year the goal was to produce a blood pressure and pulse measurement device. It was supposed to be used in elderly care since it is an inconvenience for them to have to go to a hospital just to measure their pulse and blood pressure. With this device these measurements can be made in their home environment which would help them to relax and make the measurement more accurate. A doctor would also be relieved of a lot of work since he would be able to run measurements parallel with other work and then come back to analyse them at a later point. It would also be easier to compare with previous measurements since it would be possible to store the measurements from each patient on "their own" homepage. The device is built around a Mitsubishi processor, M16C/62, and it communicates with Internet via Ethernet and Bluetooth. The report describes how the problems were solved and what was produced by the groups in the different areas such as the processor, electromechanics, user interface and Bluetooth. Antenna AB was our partner in working with this project.

  • 113.
    Carlander, Carl
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Installation effects and implications for self diagnostics for an ultrasonic flow meter1998Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 114.
    Carlander, Carl
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Installation effects and self diagnostics for ultrasonic flow measurement2001Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    In the district heating industry, heat meters, consisting among other things of a flow meter, are used for billing purpose. The district heating industry desires accurate and low cost flow measurements. There are mainly two reasons. An under estimation of the flow rate leads to a loss of income for the district heating industry. Further, the total cost for measuring, including the cost for the heat meter, the reading and the maintenance, represents a relatively large part of the total energy cost. Therefore a project concerning measurement quality assurance in district heating systems is in progress at Luleå University of Technology. As a part of this project the possibility of self diagnostic techniques for flow meters is investigated. It is well known that installation effects greatly impair the flow measurement involved in heat metering. Thus this thesis focus on self diagnostics of different installation effects. The basic assumption is that the flow meter noise level is correlated to turbulence intensity. Since the turbulence intensity is effected by installation effects, the noise level can be used to detect conditions for which the flow meter shows erroneous results. In district heating applications the use of ultrasonic flow meters are becoming more and more frequent. The self diagnostic approach has therefore been investigated for a small size prototype ultrasonic flow meter. Single and double elbow pipe bends and pipe diameter reductions mounted in front of the meter and pulsating flow give rise to small but reproducible errors. The magnitude of the maximum errors were in the range of 2 to 4% of flow rate. At low flow rates with pulsating flow the errors were larger. Also small commercial ultrasonic flow meters were investigated. These commercial meters are commonly used in heat meters in small district heating subscriber stations. The results demonstrate that both temperature changes and installation effects introduce errors in the flow measurements. By studying the noise level of the signal from the prototype ultrasonic flow meter it is clear that all installation effects tested caused a clear increase in the flow signal noise level. It is clear that no tested disturbance causing measurement errors, larger than 1% of the flow rate, will pass undetected. Neither will normal conditions with a varying flow rate or single measurement outliers cause false alarms. It is anticipated that this increase in the future can be detected on-line by the flow meter itself giving it a self diagnostic capability.

  • 115. Carlander, Carl
    et al.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Installation effects on an ultrasonic flow meter1998Ingår i: Proceedings - The 9th International Conference on Flow Measurement: FLOMEKO, Kista: ITF , 1998, s. 149-154Konferensbidrag (Refereegranskat)
  • 116. Carlander, Carl
    et al.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Installation effects on an ultrasonic flow meter with implications for self diagnostics2000Ingår i: Flow Measurement and Instrumentation, ISSN 0955-5986, E-ISSN 1873-6998, Vol. 11, nr 2, s. 109-122Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A small ultrasonic flow meter for water was exposed to five different test configurations, a reference experiment, a single elbow, a double elbow out of plane, a reduction in pipe diameter and a pulsating flow experiment. All tests were performed in a flow calibration facility ranging over Reynolds number from 25 to 110 000. The experiments with the four installation effects were compared with a reference experiment. The error and the change in standard deviation compared to the reference experiment were calculated. The standard deviation serve as a measure of the noise level of the flow meter. The results show that all disturbances generated errors in the flow measurement. The maximum errors were mainly in the range of 2–4% of flow rate, but at very low flow rates the pulsating flow caused larger errors. In most of the flow range there were no or smaller errors. All installation effects also generated an increase in the noise level. The different pipe configurations increased the standard deviation up to more than 100%. The pulsating flow induced even higher enlargements in the noise level. The errors and the increase in the standard deviation are present in about the same flow ranges. The results demonstrate not only that the installation effects tested introduce errors in the flow measurements but also that these effects can be detected from the noise level in the data. The noise level was determined from the standard deviation. This could be interpreted as that the disturbances amplify the turbulence intensity. Thus the standard deviation can be used as a measure of the turbulence. The presence of a disturbance could be recognised by comparing the magnitude of the noise level in the present data with a reference level valid for the measured flow rate. A procedure like this could possibly be performed by the meter itself in operation.

  • 117.
    Carlander, Carl
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Temperature and installation effects on small commercial ultrasonic flow meters2000Konferensbidrag (Refereegranskat)
    Abstract [en]

    Experimental work has been performed on a selection of small ultrasonic flow meters for water. This work was accomplished in order to investigate the in fluence of temperature and flow profile disturbances on the performance of flow meters in district heating applications. The flow meters tested were all ultrasonic flow meters of sing-around type. The selection of flow meters contains in total seven meters of three different brands. All meters have a flow range from 0.015 m3/h to 1.5 m3/h. These meters are commonly used in heat meters in small district heating subscriber stations. The flow meters are presented without identification. All tests were performed in a flow meter calibration facility and in a flow range including the minimum and maximum flow of each flow meter. In the tests three different water tempera-tures and three different installations were investigated. Water temperatures of 20 °C, 50 °C and 70 °C were used. These temperatures are representative for district heating applications. The installations tested involved flow meters mounted with long straight pipes both up-and down-stream representing ideal conditions, a single elbow and a double elbow out of plane both generating disturbed flow profiles. All set-ups are in accordance with the flow meter specifications. The results demonstrate that both the change in temperature and the disturbed flow profiles introduce errors in the flow measurements. The change from 20 °C to 50 °C and 70 °C can cause a shift in meter performance larger than the specified maximum permissible error. Compared with the ideal installation the installations generating disturbed flow profiles cause errors up to more than 2 %. The errors due to temperature and installation effects have a bias to add when combined. This might lead to even larger errors.

  • 118.
    Carlson, Johan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Martinsson, Pär-Erik
    Löfqvist, Torbjörn
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Håkansson, Mikael
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Castano, Miguel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Linder, Tomas
    Projekt: SCOPE Norra2011Övrigt (Övrig (populärvetenskap, debatt, mm))
    Abstract [sv]

    SCOPE Norra är ett samarbetskonsortium för forskning och utveckling tillsammans med massa- och pappersindustrin i Norrbotten och Västerbotten. Projektet koordineras av centrumbildningen ProcessIT Innovations.Inom SCOPE Norra pågår ett flertal delprojekt, uppdelat på ett antal fokusområden.Huvudfinansiär för konsortiet är Tillväxtverket genom medel från EU:s strukturfonder.

  • 119.
    Carlson, Johan E.
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Hägglund, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Characterization of thin layers in multi-layered structures: on the problem of finding starting values for numerical solutions to inverse problems2010Ingår i: 2009 IEEE Ultrasonics Symposium: Rome, Italy, 20 - 23 September 2009, Piscataway, NJ: IEEE Communications Society, 2010, s. 1537-1540Konferensbidrag (Refereegranskat)
    Abstract [en]

    Several model-based techniques have been proposed for characterizing thin layers within multi-layered materials. One problem with these methods is that the models are non-linear with respect to the parameters. Hence, iterative numerical methods must be used estimating the model parameters, i.e. for solving the inverse problem based on measurements. For material structures where the propagation times through the individual layers are shorter than the duration of the transmitted ultrasound pulse, the received waveform will consist of several overlapping echoes. For the parameter estimation to work, good initial guesses of the times of flight are required, which are difficult to obtain due to the severe overlap of the echoes. In this paper we propose a filtering scheme, that compresses the transmitted pulse into a shorter pulse, thus enabling the echoes from within the material structure to be detected. The method is evaluated using simulations on a three-layered material for varying signal-to-noise conditions.

  • 120.
    Carlson, Johan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Grennberg, Anders
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Multiphase flow characterized by scattering of ultrasound1998Ingår i: Proceedings - The 9th International Conference on Flow Measurement: FLOMEKO / [ed] Jerker Delsing, Kista: ITF , 1998, s. 493-497Konferensbidrag (Refereegranskat)
  • 121.
    Carlson, Johan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    van Deventer, Jan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    IT som stöd för optimering och energimätning i fjärrvärme- och gasnät2006Konferensbidrag (Övrigt vetenskapligt)
    Abstract [sv]

    Vid EISLAB (Embedded Internet Systems Laboratory), Luleå tekniska universitet, pågår sedan några år tillbaka ett antal projekt kopplade till energimätning. Ett projekt behandlar noggrannhet, diagnostisering och optimering av energimätningar i fjärrvärmenät. Ett annat projekt syftar till att utveckla metoder baserade på ultraljud för mätning av energiflöde och sammansättning av bio- och naturgas. Föredraget ger en sammafattning av det arbete som hittills utförts inom dessa områden samt en framåtblick över de möjligheter och fördelar resultaten från dessa projekt ger i framtiden. Inom fjärrvärmeanvändningen finns ett behov av en förbättrad mätning av energianvändningen, dels för att kunna reglera processerna och dels för att kunder och leverantörer ska betala för rätt saker. Snabb och noggrann mätning är idag inte möjligt. Ur underhållssynpunkt är det även av intresse att på distans kunna diagnosticera systemen, både på leverantörs- och kundsidan. Samma teknik kommer även att kunna användas för optimering av processen. Bio- och naturgas har utpekats som möjliga alternativ till bensin och diesel som drivmedel. De mätmetoder som finns idag för att säkerställa kvaliteten och bestämma energivärdena lämpar sig inte för användning långt ut i distributionskedjan. Målet med forskningsprojektet vid EISLAB är att utveckla en ultraljudsmetod som kan mäta sammansättning, energivärde och flöde av dessa gaser. Fokus ligger på utveckling av statistiska metoder samt fysikaliska modeller för vågutbredning i gaser. Förutom tillämpningar inom bio- och naturgas, kan tekniken även användas inom petrokemisk- och processindustri.

  • 122.
    Carlson, Johan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    van Deventer, Jan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Micella, M
    Luleå tekniska universitet.
    Accurate temperature estimation in ultrasonic pulse-echo systems2003Ingår i: 5th world congress on ultrasonics WCU 2003, Paris: Institut Biomedical des Cordeliers, Université Pierre et Marie Curie , 2003, s. 1565-1568Konferensbidrag (Refereegranskat)
    Abstract [en]

    Ultrasonic pulse-echo systems are widely used to estimate properties of liquids and gases. A common principle is to use a buffer material (buffer-rod) fixed to the ultrasound transducer. Assuming the acoustic properties of the buffer-rod are known, it is then possible to calculate the acoustic impedance of the unknown material. A problem occurs if the temperature of the buffer-rod changes during the measurements, since the properties of the buffer-rod, such as the acoustic attenuation depends on temperature. If, however, the temperature is recognized, it is possible to compensate for this. In this paper we present a method based on speed of sound changes in the buffer-rod to estimate the temperature. With the resulting model we are able to estimate temperatures in PMMA for the interval 5°C to 60°C with a 0.1 °C accuracy (at a 95% confidence level).

  • 123.
    Carlson, Johan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    van Deventer, Jan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Scolan, A
    Luleå tekniska universitet.
    Carlander, Carl
    Frequency and temperature dependence of acoustic properties of polymers used in pulse-echo systems2003Ingår i: Proceedings, 2003 IEEE Ultrasonics Symposium: October 5 - 8, 2003, Hilton Hawaiian Village, Honolulu, Hawaii ; an international symposium / / [ed] Donald E. Yuhas, Piscataway, NJ: IEEE Communications Society, 2003, s. 885-888Konferensbidrag (Refereegranskat)
    Abstract [en]

    In ultrasonic pulse-echo systems, polymers like PMMA (polymethylmethacrylate) and PEEK (polyetheretherketone) are often used as buffer-rods, placed between the ultrasound transducer and the unknown material (liquid, gas, or solid material). Provided the acoustic properties of the buffer-rods are known, it is possible to calculate these also for the unknown material, based on reflections between the buffer-rod and the unknown medium. However, temperature changes also affect these properties. In this paper we present a method for measuring acoustic attenuation, speed of sound and density, for buffer-rod materials. We also give experimental values for PMMA and PEEK, for temperatures between 5/spl deg/C and 37/spl deg/C, and for 5 MHz and 10 MHz ultrasound frequency.

  • 124.
    Carlsson, Oscar
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Enabling Large IoT Platforms in Industrial Process Automation2015Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Internet of Things is envisioned to be a cornerstone in the connected, comfortable, efficient, and productive society of tomorrow. Part of this vision is the Industrial Internet of Things where connected devices all over industrial installations, in addition to performing the duties of the automation systems of today, provide countless opportunities for improvements thanks to dynamic access to systems and information previously obscured. Looking at the history of industrial process control systems it is clear that the development of industrial systems have followed a very different path than that of consumer electronics. Among the foreseen challenges facing the European process industries in the near future are adopting to increased expectations of information availability and upgrading many of the old installations that use control systems that are facing the end of their operational life time. One of the large challenges for enabling Internet of Things in the process industries is how to preserve and improve on that which the traditional Distributed Control Systems provide while changing much or the core infrastructure and architectures from the current hierarchical structure into a flat Service Oriented Architecture. The situation is comparable to financial and other enterprise IT-systems which previously used more specialized hardware but is now comprised of specialized software running mostly on generic client and server hardware. This similarity suggests that there should be experiences from the migration of IT-systems to use as a starting point for the migration of industrial systems towards more open and dynamic solutions. This thesis presents a strategy for migrating large Distributed Control Systems, common at process industrial plants, to a Service Oriented Architecture. The strategy is comprised of four main steps wherein different parts of the system are migrated in a way that is intended to keep the plant operating with minimal disturbance and similar or improved performance throughout the migration process. Part of the first step of this strategy is illustrated with a technical demonstration at the LKAB pelletizing plant in northern Sweden. The proposed strategy is a first step towards allowing the process industry to take advantage of the opportunities provided by the technology that is anticipated to influence our society over the coming decades.

  • 125.
    Carlsson, Oscar
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB. Midroc Automation AB.
    Engineering of IoT Automation Systems2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Major societal challenges such as environmental sustainability, availability of energy and raw materials, and globalisation are creating new requirements for many actors in society. These new requirements relate to efficiency, flexibility, sustainability, and competitiveness. While these aspects have all been around for some time, and many systems have been locally optimised with regards to one or a few of these requirements, recent advances in communication and processing capabilities promise increased possibilities for connecting different parts of society, allowing optimal operation on a much larger scale.

    While industrial production systems have been controlled electronically for decades, the digitisation of market channels and consumer systems, together with the possibility to interconnect different production facilities, now allow for automated interaction along the whole supply chain from raw materials to end users.Simultaneously, increased demand for efficiency forces increased specialisation among actors, which with increased possibilities of interconnectivity, creates large enterprises of cooperating, specialised stakeholders.

    One of the major remaining obstacles for a widespread adaptation of more intelligent, more connected systems, able to deliver these envisioned results, is a coherent approach to the engineering and management of Systems-of-Systems involving very large numbers of devices and operating across several automation domains.For traditional automation systems there are established engineering procedures and numerous standards for engineering data, although most are focused on the static processes that have traditionally been the norm. For full integration with a digital society many of the existing automation systems will need significant modifications and as many automation systems are ageing and in need of replacement, a suitable solution to this may be a large scale migration to new automation solutions.

    The work presented in this thesis includes some new approaches and methodologies to utilise the existing engineering procedures and standards, while introducing some of the flexibility proposed by the emerging technologies. The major technical solutions presented consist of a structure way to organise connected systems and how they are related, regardless of engineering standards used to design their interactions, and an approach to allow configuration of heterogeneous systems through service interactions.Further contributions include an approach for migrating certain categories of existing industrial control systems to a service oriented architecture, as a basic outline for adaption of the next generation of automation systems in industry.Certain remaining challenges have been identified, which have to be addressed for a successful launch of widespread interconnected automation systems based on Internet of Things and associated technologies.

  • 126.
    Carlsson, Oscar
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB. Midroc Automation AB.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Engineering of Service-oriented IoT Automation Systems2017Ingår i: IEEE Systems Journal, ISSN 1932-8184, E-ISSN 1937-9234Artikel i tidskrift (Refereegranskat)
  • 127.
    Carlsson, Oscar
    et al.
    Midroc Electro AB, Stockholm.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Arrigucci, Fredrik
    Midroc Electro AB, Stockholm.
    Colombo, Armando Walter
    University of Applied Sciences Emden & Schneider Electric, Emden.
    Bangemann, Thomas
    IFAK, Magdeburg, Germany.
    Nappey, Philippe
    Schneider Electric, Grenoble, France.
    Migration of industrial process control systems to service-oriented architectures2018Ingår i: International journal of computer integrated manufacturing (Print), ISSN 0951-192X, E-ISSN 1362-3052, Vol. 31, nr 2, s. 175-198Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The use of Service Oriented Architectures (SOAs) in industrial automation promises an improved cross-layer integration as well as a functionality decoupled from the technical implementation. Compared with the earlier investigated manufacturing industry, control systems in the process industry reveal additional challenges in terms of migration from a legacy control system to an SOA control system.

    The successful migration of a highly integrated process control system, without reducing reliability or availability and, at the same time, preserving functionality and productivity, requires a detailed plan and certain specialised technology.

    This paper presents the challenges in the migration of a process control system and proposes a structured method for migration. The migration procedure proposed comprises four steps: initiation, configuration, data processing, and control execution. A technology demonstration at a pelletizing plant illustrates how the first of these steps could be implemented.

  • 128.
    Carlsson, Oscar
    et al.
    Midroc Automation AB.
    Hegedűs, Csaba
    AITIA International, Inc..
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Varga, Pal
    Budapest University of Technology and Economics.
    Organizing IoT Systems-of-Systems from Standardized Engineering Data2016Ingår i: IECON Proceedings (Industrial Electronics Conference), Piscataway, NJ: IEEE Computer Society, 2016, s. 5277-5282, artikel-id 7792932Konferensbidrag (Refereegranskat)
    Abstract [en]

    Tackling current challenges in production automation requiresthe involvement of new concepts like Internet of Things,System-of-Systems and local automation clouds.The objective of this paper is to address the actual process of defining a cloud based automation system. More specifically the design, engineering, operation and maintenance of an automation system must be captured and managed between all stakeholders involved. This is critical to create the expected benefits from the local automation cloud approach.This paper addresses the capability of capturing plant designs and coordinating information exchange based on the captured architecture.For this purpose an architectural component --~Plant Description~-- is proposed to be used in the Arrowhead Framework, based on already existing plant automation standards.An overview of methodologies on how it can interact with the Arrowhead Framework's Orchestration process describes the usefulness in managing large-scale automation systems.A qualitative evaluation for one of the proposed approaches is also described in a water control use case that can be found both in process and building automation.

  • 129.
    Carlsson, Oscar
    et al.
    Midroc Automation AB.
    Puñal Pereira, Pablo
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Eliasson, Jens
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ahmad, Bilal
    Automation Systems Group, WMG, the University of Warwick Coventry, United Kingdom.
    Harrison, Robert
    Automation Systems Group, WMG, the University of Warwick Coventry, United Kingdom.
    Jansson, Ove
    Abelko Innovation.
    Configuration Service in Cloud based Automation Systems2016Ingår i: IECON Proceedings (Industrial Electronics Conference), Piscataway, NJ: IEEE Computer Society, 2016, s. 5238-5245, artikel-id 7793489Konferensbidrag (Refereegranskat)
    Abstract [en]

    Current challenges in production automation requires the involvement of new technologies like Internet of Things (IoT), Systems of Systems and local automation clouds. The objective of this paper is to address one of the challenges involved in establishing and managing a cloud based automation system. Three key capabilities have been identified as required to create the expected benefits of local automation clouds; 1) capturing of plant design 2) capturing and distributing configuration and deployment information 3) coordinating information exchange.

    This paper addresses the capturing and distribution of configuration and deployment information. For this purpose a system service is proposed, the ConfigurationStore, following the principles of the Arrowhead Framework. The service is accompanied by a deployment methodology and a bootstrapping procedure. These are discussed for several types of automation technology, e.g. controllers, sensors, actuators. A qualitative evaluation of the proposed approach is made for four use cases; Building automation, Manufacturing automation, Process automation and IoT devices. Concluding the usability for large-scale deployment and configuration of Industrial Internet of Things.

  • 130.
    Carlsson, Oscar
    et al.
    Midroc Electro AB, Stockholm.
    Vera, Daniel
    Fully Distributed Systems Ltd .
    Arceredillo, Eduardo
    Fundacion Tekniker .
    Tauber, Markus G.
    Fachhochschule Burgenland GmbH .
    Ahmad, Bilal
    University of Warwick.
    Schmittner, Christoph
    Austrian Institute of Technology.
    Plosz, Sandor
    Austrian Institute of Technology.
    Ruprechter, Thomas
    Infineon Technologies AG.
    Aldrian, Andreas
    AVL List GmbH.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Engineering of IoT automation systems2017Ingår i: IoT Automation: Arrowhead Framework / [ed] Jerker Delsing, Boca Raton, FL: CRC Press , 2017, , s. 366s. 161-211Kapitel i bok, del av antologi (Refereegranskat)
  • 131.
    Carlsson, Oscar
    et al.
    Midroc Automation AB.
    Vera, Daniel
    Fully Distributed Systems Ltd..
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ahmad, Bilal
    Automation Systems Group, WMG, the University of Warwick.
    Harrison, Robert
    University of Warwick, Coventry.
    Plant descriptions for engineering tool interoperability2017Ingår i: IEEE International Conference on Industrial Informatics (INDIN), Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 730-735, artikel-id 7819255Konferensbidrag (Refereegranskat)
    Abstract [en]

    The emergence and deployment of connected devices in many domains of application (e.g. industrial production, buildings and facilities, urban environment, etc.) have resulted in the need to achieve integration of multiple and more complex systems. This new environment is stressing the intrinsic limits imposed by monolithic standards, data models and integration methods that focus on specific domains of application, types of systems, or specific aspects of a system. This paper describes the Plant Description Service developed as part of the Arrowhead Interoperability framework (EU ECSEL funded project). The manuscript contains a description of the abstract system descriptive model based on which the Plant Description service was implemented, and describes how the service can be used to achieve integration of several industry standards and data models. One use case and one case study is provided that illustrates how the service was practically implemented to support engineering scenarios in the domain of industrial production. The paper concludes with a critical review of the approach and suggestion for future work and developments.

  • 132.
    Carr-Motyckova, Lenka
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Fransson, Pierre
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    An Incremental Algorithm for Calculation of Backup Routes in Link-State Networks2003Ingår i: Swedish National Computer Networking Workshop - Proceedings: SNCNW 2003, Stockholm, 2003Konferensbidrag (Övrigt vetenskapligt)
  • 133.
    Carr-Motyckova, Lenka
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap. Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Johansson, Tomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    On clustering in ad hoc networks2003Ingår i: Swedish National Computer Networking Workshop - Proceedings: SNCNW 2003, Stockholm, 2003Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    This paper presents the reasons for clustering algorithms in ad hoc networks, as well as a short survey of the basic ideas and priorities of existing clustering algorithms. A new algorithm is presented. It makes it possible to define a limit for the maximum size of the clusters as well as the maximum number of hops between a node and its clusterhead.

  • 134.
    Casselgren, Johan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Rosendahl, Sara
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Eliasson, Jens
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Road surface information system2013Ingår i: Proceedings of the 16th SIRWEC conference: Helsinki, FInland (23-25th May 2012), Standing International Road Weather Commission , 2013Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In order to classify the road condition, dry asphalt and asphalt covered with water, ice and snow a technique using a sensor called Road eye is presented. The Road eye sensor uses three wavelengths and one photo detector to determine the intensities that are reflected from the road surface and is then able to estimate the road condition. By linking the Road eye sensor to a GPS and a Mulle, a miniature wireless Embedded Internet System, the road conditions can be associated with the correct road position, making it possible to use the information in many different applications.

  • 135.
    Charlier, Maximilien
    et al.
    Computer Science Department, University of Mons.
    Quoitin, Bruno
    Computer Science Department, University of Mons.
    Bette, Sebastien
    Engineering Faculty, University of Mons.
    Eliasson, Jens
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Support for IEEE 802.15.4 Ultra Wideband Communications in the Contiki Operating System2016Ingår i: IEEE Symposium on Communications and Vehicular Technology in the Benelux (SCVT), Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2016, artikel-id 7797662Konferensbidrag (Refereegranskat)
    Abstract [en]

    The use of UWB for Industrial Internet of Things (IIoT) applications benefits from the following four main properties; 1) scalability due to the inherent short transmissions times of the UWB radio, 2) bandwidth-consuming applications such as condition monitoring with vibration sensing, 3) applications with real-time positioning (RTLS) requirements, and 4) wireless communication in electromagnetically harsh environments with a high level of multipath fading. In this paper, we present a UWB-based 6LoWPAN implementation in the Contiki OS as a step towards incorporating UWB in the industrial IoT domain.

  • 136.
    Chou, S.M.
    et al.
    Clayton School of Information Technology, CSIT, Monash University.
    Papliński, A.P
    Clayton School of Information Technology, CSIT, Monash University.
    Gustafsson, Lennart
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Speaker-dependent bimodal integration of Chinese phonemes and letters using multimodal self-organizing networks2007Ingår i: The 2007 IEEE International Joint Conference on Neural Networks: [IJCNN 2007] ; Orlando, FL, 12 - 17 August 2007, Piscataway, NJ: IEEE Communications Society, 2007, s. 248-253Konferensbidrag (Refereegranskat)
    Abstract [en]

    We present a model of integration of auditory and visual information as in the human cortex. More specifically, we demonstrate a possible way in which the phonetic symbols and associated Mandarin Chinese phonemes pronounced by different speakers are mapped onto the model of cortical areas. Our model has been strongly influenced by recent fMRI studies on integration of letters and speech sounds in the human brain. The model is based on multimodal self-organizing networks (MuSoNs) which were introduced in our previous works and proved to be a convenient tool to describe and study mapping and integration of sensory information as in the cortex. The model also shows how phonemes pronounced by different speakers are mapped onto overlapping cortical areas

  • 137.
    Chouhan, Shailesh
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Halonen, Kari
    Department of Micro and Nano Sciences, School of Electrical Engineering, Aalto University.
    A 352nW, 30 ppm/°C all MOS nano ampere current reference circuit2017Ingår i: Microelectronics Journal, ISSN 0959-8324, Vol. 69, s. 45-52Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, an ultra low power all-MOSFET based current reference circuit, developed in 0.18 µm CMOS technology, is presented. The proposed circuit is based on the classical resistor-less beta multiplier circuit with an additional temperature compensation feature. The circuit is capable of providing the reference current in a nanoampere range for the supply voltage ranging from 1 V to 2 V in the industrial temperature range of −40 °C to 85 °C. The measurements were performed on 10 prototypes. The measured mean value of the reference current is 58.7 nA with a mean temperature coefficient value of 30 ppm/°C. In addition, the measured mean line regulation is 3.4%/V in the given supply voltage range. The total current consumption of the circuit is 352 nA and the chip area is 0.036 mm2.

  • 138.
    Chouhan, Shailesh Sing
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Halonen, Kari
    Department of Micro-and Nanosciences, School of Electrical Engineering, Aalto University .
    Ultra low power beta multiplier-based current reference circuit2017Ingår i: Analog Integrated Circuits and Signal Processing, ISSN 0925-1030, E-ISSN 1573-1979, Vol. 93, nr 3, s. 523-529Artikel i tidskrift (Refereegranskat)
    Abstract [en]

     This work presents a current reference circuit fabricated in a standard 0.18 μm CMOS technology. The reference current is obtained by applying thermal compensation voltage in the conventional self-biased or beta multiplier-based current reference circuit. Eight prototypes of the proposed architecture were measured which have resulted into the mean reference current of 26.1 nA with the temperature coefficient of 202.1 ppm/°C. These measurements were performed in the temperature range of − 40 to + 85 °C. The circuit is capable of working over the supply voltage range of 1–2 V with the measured mean line sensitivity of 2.18%/V. The maximum measured power dissipation of the circuit is 104 nW at 2 V.

  • 139.
    Chu, Tianxing
    et al.
    University of Colorado, Boulder.
    Vinande, Eric
    University of Colorado, Boulder.
    Akos, Dennis
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Weinstein, Brian
    University of Colorado, Boulder.
    GNSS receiver evaluation: record-and-playback test methods2010Ingår i: GPS World, ISSN 1048-5104, Vol. 21, nr 1, s. 28-34Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Researchers at the university of Colorado have successfully used radio frequency record-and-playback systems (RPS) have gathered importance commercially because it offers the best way to test hardware receivers. RPS constitutes a stark contrast to more traditional signal simulators that use pre-defined trajectories and mathematical models to determine appropriate RF output. Positioning performance of a satellite navigation receiver under test (RUT) is coupled with its RF front-end system and local oscillator quality. The required equipment and connections are minimal when performing RPS drive testing, as no RUTs are included. It overcomes the fidelity limits of simulator-based testing, especially when considering the difficult-to-model urban environment. During receiver development, it requires only a single drive test for each location, as sampled RF data can be replayed from disk

  • 140. Ciarcelluti, Paolo
    et al.
    Sandin, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Does neutron stars have a dark matter core?2010Rapport (Övrigt vetenskapligt)
  • 141. Ciarcelluti, Paolo
    et al.
    Sandin, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Have neutron stars a dark matter core?2011Ingår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 695, nr 1-4, s. 19-21Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent observational results for the masses and radii of some neutron stars are in contrast with typical observations and theoretical predictions for "normal" neutron stars. We propose that their unusual properties can be interpreted as the signature of a dark matter core inside them. This interpretation requires that the dark matter is made of some form of stable, long-living or in general non-annihilating particles, that can accumulate in the star (Sandin and Ciarcelluti (2009). In the proposed scenario all mass-radius measurements can be explained with one nuclear matter equation of state and a dark core of varying relative size. This hypothesis will be challenged by forthcoming observations and could eventually be a useful tool for the determination of dark matter.

  • 142.
    Ciccozzi, Federico
    et al.
    Mälardalen University.
    Cicchetti, Antonio
    Mälardalen University.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Seceleanu, Tiberius
    ABB Corporate Research.
    Åkerberg, Johan
    ABB Corporate Research.
    Carlsson, Lars Eric
    Boliden AB.
    Integrating wireless system into process industry and business management2010Ingår i: IEEE Conference on Emerging Technologies and Factory Automation (ETFA), Piscataway, NJ: IEEE Communications Society, 2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    We analyze here the topic of integration, in the area of process automation, from sensor/actuator levels to plant management levels. The communication at fieldbus level is based on wireless technology while management applications run in wired control systems, but can also be distributed, communicating via the Internet. This work aims at building a real-life demonstrator at Boliden, a mining and smelting plant located in Boliden, Sweden. A small process control environment is to be deployed at the plant to supervise a tank level control system. Targeted results are an interface between wireless and wired systems, the deployment of a wireless process control environment at Boliden, and the development of the enterprise business management facilities

  • 143.
    Classon, Lars-Åke
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Elektroniskt styrd gruppmikrofon: selektering av ljudinformation med hjälp av signalprocessorer och en rad av mikrofoner1989Rapport (Övrigt vetenskapligt)
  • 144.
    Colombo, Armando W.
    et al.
    Schneider Electric, Marktheidenfeld.
    Bangemann, ThomasIfak - Institut für Automation und Kommunikation.Karnouskos, StamatisSAP Research, Karlsruhe.Delsing, JerkerLuleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.Stluka, PetrHoneywell, Prague.Harrison, RobertUniversity of Warwick, Coventry.Jammes, FrançoisSchneider Electric, Grenoble.Lastra, José Luis MartínezInstitute of Production Engineering, Tampere University of Technology.
    Industrial Cloud-Based Cyber-Physical Systems: The IMC-AESOP Approach2014Samlingsverk (redaktörskap) (Refereegranskat)
    Abstract [en]

    This book presents cutting-edge emerging technologies and approaches in the areas of service-oriented architectures, intelligent devices and cloud-based cyber-physical systems. It provides a clear view on their applicability to the management and automation of manufacturing and process industries. It offers a holistic view of future industrial cyber-physical systems and their industrial usage and also depicts technologies and architectures as well as a migration approach and engineering tools based on these. By providing a careful balance between the theory and the practical aspects, this book has been authored by several experts from academia and industry, thereby offering a valuable understanding of the vision, the domain, the processes and the results of the research. It has several illustrations and tables to clearly exemplify the concepts and results examined in the text and these are supported by four real-life case-studies. We are witnessing rapid advances in the industrial automation, mainly driven by business needs towards agility and supported by new disruptive advances both on the software and hardware side, as well as the cross-fertilization of concepts and the amalgamation of information and communication technology-driven approaches in traditional industrial automation and control systems. This book is intended for technology managers, application designers, solution developers, engineers working in industry, as well as researchers, undergraduate and graduate students of industrial automation, industrial informatics and production engineering. © 2014 Springer International Publishing Switzerland. All rights are reserved.

  • 145.
    Cottet, Didier
    et al.
    ABB Corporate Research.
    Stevanovic, Ivica
    ABB Corporate Research.
    Wunsch, Bernhard
    ABB Corporate Research.
    Daroui, Danesh
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Antonini, Giulio
    University of L’Aquila.
    EM simulation of planar bus bars in multi-level power converters2012Ingår i: EMC Europe 2012: International Symposium on Electromagnetic Compatibillity, September 15-21, Rome, Italy, 2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents recent progress in the acceleration of PEEC based electromagnetic simulations and its impact on the design of complex bus bar structures as used in multi-level power converters. The approach presented consists of providing different dedicated acceleration methods for the different design tasks. The first acceleration technique applied is the so called reluctance matrix method for full 3D field results, reducing memory consumption by orders of magnitude and computing time by a factor 3 to 5. The second acceleration method applied is based on model order reduction techniques for port-to-port impedance extraction, reducing the computation time by several orders of magnitude and allowing wideband macro modeling for system level simulations. The paper focuses on the application of these methods showing the impact on practical bus bar design tasks

  • 146.
    Dadhich, Siddharth
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    A Survey in Automation of Earth-moving Machines2015Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The earth-moving machines are used in many industries such as mining, construction,forestry, agriculture and cleaning. In underground mines, wheel loadersor LHD machines are used to move the blasted rock to a dumping site oronto a dumper truck. In presence of a nearby dumping truck, the wheel loaderis said to be operating in a short loading cycle. This research work concernswith moving of fragmented rock by a wheel loader in a short loading cycle.Three decades of research efforts in automation for bucket loading operationhas not yet yielded in any commercial fully autonomous system for this applicationdue to the complexity of bucket-environment interactions. In this report,the challenges in automation and remote-operation of earth-moving machineshave been highlighted. A survey in different areas of research within the scopeof the project is conducted and knowledge gaps have been identified to give thedirection to future work. A plan of actions is made to conduct the proposedresearch starting from a basic remote control setup to a more advanced assistedremote control operation for a wheel loader in short loading cycle.

  • 147.
    Dadhich, Siddharth
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Automation of Wheel-Loaders2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Automation and tele-remote operation of mobile earth moving machines is desired for safety and productivity reasons. With tele-operation and automation, operators can avoid harsh ergonomic conditions and hazardous environments with poor air quality, and the productivity can in principle be improved by saving the time required to commute to and from work areas. Tele-remote operation of a wheel-loader is investigated and compared with manual operation, and it is found that the constrained perception of the machine is a challenging problem with remote operations. Real-time video transmission over wireless is difficult, but presents a way towards improving the remote operator’s quality of experience. To avoid glitches in the real-time video, arising from variable wireless conditions, the use of SCReAM (Self-Clocked Rate Adaptation for Multimedia) protocol is proposed. Experiments with a small scale robot over LTE show the usefulness of SCReAM for time-critical remote control applications. Automation of the bucket-filling step in the loading cycle of a wheel-loader has been an open problem, despite three decades of research. To address the bucket-filling problem, imitation learning has been applied using expert operator data, experiments are performed with a 20-tonne Volvo L180H wheel-loader and an automatic bucket-filling solution is proposed, developed and demonstrated in field-tests. The conducted experiments are in the realm of small data (100 bucket-filling examples), shallow time-delayed neural-network (TDNN), and a wheel-loader interacting with a non-stationary pile-environment. The total delay length of the TDNN model is found to be an important hyperparameter, and the trained and tuned model comes close to the performance of an expert operator with slightly longer bucket-filling time. The proposed imitation learning trained on medium coarse gravel succeeds in filling buckets in a gravel cobble pile. However, a general solution for automatic bucket-filling needs to be adaptive to possible changes in operating conditions. To adapt an initial imitation model for unseen operating conditions, a reinforcement learning approach is proposed and evaluated. A deterministic actor-critic algorithm is used to update actor (control policy) and critic (policy evaluation) networks. The experiments show that by use of a carefully chosen reward signal the models learns to improve and maximizes bucket weights in a gravel-cobble pile with only 40 bucket-filling trials. This shows that an imitation learning based bucket-filling solution equipped with a reinforcement learning agent is well suited for the continually changing operating conditions found in the construction industry. The results presented in this thesis are a demonstration of the use of artificial intelligence and machine learning methods for the operation of construction equipment. Wheel-loader OEMs can use these results to develop an autonomous bucket-filling function that can be used in manual, tele-remote or fully autonomous operations.

  • 148.
    Dadhich, Siddharth
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Bodin, Ulf
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Andersson, Ulf
    Luleå tekniska universitet, Institutionen för system- och rymdteknik.
    Key challenges in automation of earth-moving machines2016Ingår i: Automation in Construction, ISSN 0926-5805, E-ISSN 1872-7891, Vol. 68, s. 212-222Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A wheel loader is an earth-moving machine used in construction sites, gravel pits and mining to move blasted rock, soil and gravel. In the presence of a nearby dump truck, the wheel loader is said to be operating in a short loading cycle. This paper concerns the moving of material (soil, gravel and fragmented rock) by a wheel loader in a short loading cycle with more emphasis on the loading step. Due to the complexity of bucket-environment interactions, even three decades of research efforts towards automation of the bucket loading operation have not yet resulted in any fully autonomous system. This paper highlights the key challenges in automation and tele-remote operation of earth-moving machines and provides a survey of different areas of research within the scope of the earth-moving operation. The survey of publications presented in this paper is conducted with an aim to highlight the previous and ongoing research work in this field with an effort to strike a balance between recent and older publications. Another goal of the survey is to identify the research areas in which knowledge essential to automate the earth moving process is lagging behind. The paper concludes by identifying the knowledge gaps to give direction to future research in this field.

  • 149.
    Dadhich, Siddharth
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Bodin, Ulf
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Sandin, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Andersson, Ulf
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    From Tele-remote Operation to Semi-automated Wheel-loader2018Ingår i: International Journal of Electrical and Electronic Engineering and Telecommunications, ISSN 2319-2518, Vol. 7, nr 4, s. 178-182Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents experimental results with tele-remote operation of a wheel-loader and proposes a method to semi-automate the process. The different components of the tele-remote setup are described in the paper. We focus on the short loading cycle, which is commonly used at quarry and construction sites for moving gravel from piles onto trucks. We present results from short-loading-cycle experiments with three operators, comparing productivity between tele-remote operation and manual operation. A productivity loss of 42% with tele-remote operation motivates the case for more automation. We propose a method to automate the bucket-filling process, which is one of the key operations performed by a wheel-loader.

  • 150.
    Dadhich, Siddharth
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Bodin, Ulf
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Sandin, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Andersson, Ulf
    Machine Learning approach to Automatic Bucket Loading2016Ingår i: 24th Mediterranean Conference on Control and Automation (MED): June 21-24, Athens, Greece, 2016, Piscataway, NJ: IEEE Communications Society, 2016, s. 1260-1265, artikel-id 7535925Konferensbidrag (Refereegranskat)
    Abstract [en]

    The automation of bucket loading for repetitive tasks of earth-moving operations is desired in several applications at mining sites, quarries and construction sites where larger amounts of gravel and fragmented rock are to be moved. In load and carry cycles the average bucket weight is the dominating performance parameter, while fuel efficiency and loading time also come into play with short loading cycles. This paper presents the analysis of data recorded during loading of different types of gravel piles with a Volvo L110G wheel loader. Regression models of lift and tilt actions are fitted to the behavior of an expert driver for a gravel pile. We present linear regression models for lift and tilt action that explain most of the variance in the recorded data and outline a learning approach for solving the automatic bucket loading problem. A general solution should provide good performance in terms of average bucket weight, cycle time of loading and fuel efficiency for different types of material and pile geometries. We propose that a reinforcement learning approach can be used to further refine models fitted to the behavior of expert drivers, and we briefly discuss the scooping problem in terms of a Markov decision process and possible value functions and policy iteration schemes.

1234567 101 - 150 av 1000
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • 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