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  • 1.
    Schweiger, Gerald
    et al.
    Graz University of Technology, Austria.
    Nilsson, Henrik
    University of Nottingham, UK.
    Schöggl, Josef Peter
    KTH, Royal Institute of Technology, Sweden.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Posch, Alfred
    University of Graz, Austria.
    Modeling and simulation of large-scale systems: A systematic comparison of modeling paradigms2020Ingår i: Applied Mathematics and Computation, ISSN 0096-3003, E-ISSN 1873-5649, Vol. 365, artikel-id 124713Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    A trend across most areas where simulation-driven development is used is the ever in- creasing size and complexity of the systems under consideration, pushing established methods of modeling and simulation towards their limits. This paper complements existing surveys on large-scale modeling and simulation of physical systems by conducting expert surveys. We conducted a two-stage empirical survey in order to investigate research needs, current challenges as well as promising modeling and simulation paradigms. Furthermore, we applied the analytic hierarchy process method to prioritise the strengths and weak- ness of different modeling paradigms. The results of this study show that experts consider acausal modeling techniques to be suitable for modeling large scale systems, while causal techniques are considered less suitable.

  • 2.
    Lucchese, Riccardo
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A study of fine and coarse actuation capabilities in air-cooled server racks: control strategies and cost analysis2019Ingår i: IEEE Transactions on Control Systems Technology, ISSN 1063-6536, E-ISSN 1558-0865Artikel i tidskrift (Refereegranskat)
  • 3.
    Lucchese, Riccardo
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Computing the allowable uncertainty of sparse control configurations2019Ingår i: Journal of Process Control, ISSN 0959-1524, E-ISSN 1873-2771Artikel i tidskrift (Refereegranskat)
  • 4.
    Birk, Wolfgang
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Atta, Khalid
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Udén, Fredrik
    Improving District Heating System Operation through Control Configuration Selection and Adaptive Control2019Ingår i: 2019 18th European Control Conference (ECC), 2019, s. 2944-2949Konferensbidrag (Refereegranskat)
  • 5.
    Lucchese, Riccardo
    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.
    On the allowable uncertainty in control configuration selection2019Konferensbidrag (Övrigt vetenskapligt)
  • 6.
    Lindström, John
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Digitala tjänster och system.
    Lejon, Erik
    Gestamp Hardtech AB.
    Kyösti, Petter
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Mecella, Massimo
    University of Sapienza.
    Heutelbeck, Dominic
    FTK.
    Hemmje, Matthias
    FTK.
    Sjödahl, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gunnarsson, Bengt
    Data Ductus AB.
    Towards intelligent and sustainable production systems with a zero-defect manufacturing approach in an Industry4.0 context2019Ingår i: Procedia CIRP, vol 81 / [ed] Edited by Peter Butala, Edvard Govekar, Rok Vrabič, Elsevier, 2019, Vol. 81, s. 880-885Konferensbidrag (Refereegranskat)
    Abstract [en]

    The paper addresses intelligent and sustainable production achieved through combination and integration of online predictive maintenance, monitoring of process parameters and continuous quality control of both input materials and output from the process. This enables production systems, within both manufacturing and process industries, to move towards zero-defect manufacturing. Such a zero-defect manufacturing approach allows for earlier identification of problems or issues, which will or already negatively affect the output. The paper outlines the first part of the second cycle of an action research effort at Gestamp HardTech AB in Sweden, whose objective is to keep its position as a world-leading provider of press-hardened vehicle parts. In order to fully implement the zero-defect manufacturing approach, 4-6 action research cycles are expected to be needed in order to iteratively refine the approach. During the first cycle, various methods and solutions for some of the individual issues/problems have been conceptualized, realized and initially tested. The selected design criteria for the action research efforts were: simplicity, low cost, robustness, high-quality output and future-proofing. The result from the research in the second cycle so far is an action plan for the technical change and a set of challenges/problems which need additional investigation.

  • 7.
    Loureiro, Tatiana
    et al.
    R2M Solution, Pavia, Italy.
    Rämä, Miika
    VTT Technical Research Centre of Finland, Espoo, Finland.
    Sterling, Raymond
    NUIG,Department of Civil Engineering, Galway, Ireland.
    Cozzini, Marco
    EURAC Research, Bolzano, Italy.
    Vinyals, Meritxell
    CEA, Gif‐sur‐Yvette CEDEX, Paris, France.
    Descamps, Michael
    CEA, Gif‐sur‐Yvette CEDEX, Paris, France.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Unkaya, Gozde
    Exergy, Coventry Innovation Village, CUTP, Coventry, UK.
    Fuligni, Federica
    Exergy, Coventry Innovation Village, CUTP, Coventry, UK.
    Doračić, Borna
    University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Zagreb, Croatia.
    Petrovic, Marin
    Municipality of Visoko, Visoko, Bosnia and Herzegovina.
    Rutz, Dominik
    WIP Renewable Energies, Munich, Germany.
    Arias, Inés
    DHC+ Technology Platform/Euroheat & Power, Brussels, Belgium.
    Lettenbichler, Sofia
    DHC+ Technology Platform/Euroheat & Power, Brussels, Belgium.
    Meintanis, Ioannis
    City University of London, Systems & Control Research Centre, London, UK.
    Moustakidis, Serafeim
    City University of London, Systems & Control Research Centre, London, UK.
    Buchholz, Martin
    Watergy, Berlin, Germany.
    Buchholz, Reiner
    TU Berlin, Institute for Energy Technology, Berlin, Germany.
    Provost, Mathieu
    TU Berlin, Institute for Energy Technology, Berlin, Germany.
    Geyer, Philipp
    KU Leuven, Department of Architecture, Leuven, Belgium.
    District Energy Systems: A Collaborative Exchange of Results on Planning, Operation and Modelling for Energy Efficiency2018Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Workshop organized by INDIGO project as a collaborative activity among EU funded projects in the area of District Heating and Cooling. The objective of the workshop was twofold: (1) to create a cluster of European funded projects working in the area of District Energy Systems; and (2) to create a networking opportunity in which to share experiences on the results and difficulties of the researches, and to identify synergies.

  • 8.
    Moaveni, Bijan
    et al.
    Iran University of Science and Technology,Tehran.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Modified Hankel Interaction Index Array for Input-Output Pairing with Improved Characteristics2018Ingår i: IFAC-PapersOnLine: 10th IFAC Symposium on Advanced Control of Chemical Processes ADCHEM 2018, Elsevier, 2018, Vol. 51, s. 452-457Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this study, a modified version of Hankel Interaction Index Array (HIIA) for control configuration selection is presented which can overcome some of its shortcomings, like e.g. scaling dependency, or not relating to closed loop system properties. Inspired by the relative gain array approach, the HIIA is reformulated in the relative gain thinking by considering the effect of closing loops. The ratio of the Hankel norm of the subsystems in closed and open loop are used to state a modified version of HIIA, which has improved characteristics compared to the original HIIA. Properties of the modified HIIA are discussed and benchmarked with established methods on three example cases.

  • 9.
    Castaño Arranz, Miguel
    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.
    Kadhim, Ali
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    On Guided and Automatic Control Configuration Selection2018Ingår i: IEEE International Conference on Emerging Technologies and Factory Automation (ETFA), Piscataway, Nj: Institute of Electrical and Electronics Engineers (IEEE), 2018, Vol. F134116Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper discusses the guided and automatic control configuration selection in large scale complex systems. Due to the trend of increasesd level of automation and connectedness which is promoted by the Industry 4.0 strategy and supported by technologies relating to cyber-physical systems and the industrial internet of things, selecting appropriate control strategies becomes increasingly important and complex. This is especially important as a control strategies will limit the achievable performance of the process system, and there are  trade-offs between complexity of the control strategies, achievable performance, vulnerability and maintainability.

    The paper reviews the state of the art of methodologies that support the practitioners in taking decisions on control strategies, where two main approaches are considered, the guided one and a fully automatic one. It is shown how both approached can be conducted and examples are used to clarify the selection process.

  • 10.
    Atta, Khalid
    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.
    Utilization of Generic Consumer Modeling in Planning and Optimization of District Heating and Cooling Systems2018Ingår i: Proceedings of the 21st Nordic Process Control Workshop / [ed] Kurt-Erik Häggblom, 2018Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    District heating and cooling (DHC) networks are large scale complex systems which aregenerally difficult to operate and optimize. The large thermal inertia in the systems leadsto long reaction times on changes at the consumer side, which means that forecasting ofconsumer behaviour is a needed tool for efficient operation. Within the European Unionmany major research project target the energy reduction on the consumption side and peakload management while maintaining customer satisfaction.The optimal operation of a DHC network can therefore be considered as an interestingarea of investigation due to a number of aspects, like (i) the vast amount of the energy that is distributed by these networks, (ii) the demand to provide a better quality of services by the operators of these networks, and (iii) compliance with new environmental regulations. In this presentation, we discuss a possible conceptual method that utilizes a simpliedstatic model of different types of consumers in the network to design a decision supportsystem that will guide the operators of the DHC network to optimally operate the networkwith different operational scenarios that include but not limited to: (i) energy consumptionminimization, (ii) economic operation, (iii) peak load reduction/shifting, and (iv) environmentally friendly operation. In its current form, the operator will be informed, while in thefuture these actions could be fully automated in a closed loop context.The DHC network in Luleå, Sweden will be used as a test case which represents a typicalmedium size network. The case has a number of properties which motivate its study likee.g. the distributed generation possibilities, the geographical distribution of the consumers,and the different types of consumers in the area. The presentation will be concluded with anoutlook on future tracks of research and development

  • 11.
    Castaño Arranz, Miguel
    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.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A Survey on Control Configuration Selection and New Challenges in Relation to Wireless Sensor and Actuator Networks2017Ingår i: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, nr 1, s. 8810-8825Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This survey on Control Configuration Selection (CCS) includes methods based on relative gains, gramian-based interaction measures, methods based on optimization schemes, plantwide control, and methods for the reconfiguration of control systems. The CCS problem is discussed, and a set of desirable properties of a CCS method are defined. Open questions and research tracks are discussed, with the focus on new challenges in relation to the emerging area of Wireless Sensors and Actuator Networks.

  • 12.
    Kadhim, Ali
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system. Department of Electrical Engineering, University of Kufa, Najaf, Iraq.
    Castaño Arranz, Miguel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Automated Control Configuration Selection Considering System Uncertainties2017Ingår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 56, nr 12, s. 3347-3359Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper proposes an automated pairing approach for configuration selection of decentralized controllers which considers system uncertainties. Following the Relative Interaction Array (RIA) pairing rules, the optimal control configuration, i.e. the configuration that fits best the pairing rules, is obtained automatically by formulating the control configuration selection problem as an Assignment Problem (AP). In this AP, the associated costs related to each input-output pairing are given by the RIA coefficients. The Push-Pull algorithm is used to solve the AP for the nominal system and to obtain the set of costs for which the resulting configuration remains optimal, also called the perturbation set. The introduction of uncertainty bounds on the RIA-based costs enables the testing of the possible violation of the optimality conditions. Examples to illustrate the proposed approach for a 3×3 system and 4×4 gasifier plant are given.

  • 13.
    Castaño Arranz, Miguel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kadhim, Ali
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    On Guided and Automatic Control Configuration Selection: Application on a Secondary Heating System2017Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This technical report provides supplementary materialto the research paper entitled ”On Guided and AutomaticControl Configuration Selection”, presented at the ETFA 2017.In that paper, different Control Configuration Selection (CCS)tools are reviewed and integrated into guided and automaticCCS methodologies. The guided CCS is a heuristic step-by-stepmethodology to be applied by practitioners, while the automaticCCS methodologies target the adaptation of such heuristicsinto algorithms which can be run in a computer and assist thepractitioners in the decision making. This report summarizesthe results of applying the introduced methodologies to a reallifeprocess: the Secondary Heating System. For an introductorybackground, preliminaries, and details on the methodologies,the reader is referred to the original research paper.

  • 14.
    Castaño Arranz, Miguel
    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.
    Online Automatic and Robust Control Configuration Selection2017Ingår i: 2017 25th Mediterranean Conference on Control and Automation, MED 2017, Piscataway, NJ: IEEE, 2017, s. 1367-1372, artikel-id 7984309Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a complete method for automatic and robust control configuration selection for linear systems which relies upon acquired process data under gaussian noise excitation.

    The selection of the configuration  is based on the estimation of the Interaction Measure named Participation Matrix. This estimation is derived with uncertainty bounds, which allows to  determine online whether the uncertainty is sufficiently low to derive a robust decision on the control configuration to be used or if the uncertainty should be reduced  by e.g. prolonging the experiment to obtain more data.

  • 15.
    Birk, Wolfgang
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Castaño Arranz, Miguel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Moaveni, Bijan
    Control and Signaling Department, Iran University of Science and Technology.
    Perspectives and Future Directions in Control Configuration Selection (PiCCS): Workshop Notes2017Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The PiCCS workshop took place at Luleå University of Technology on 16th and 17th of August 2017. In total 20 researcher and engineers from industry participated in the event.

    The main aim of the workshop was to bring together expert in the field of Control Configuration Selection (CCS), which is a sub-field in the research area Automatic Control, to discuss the current state of the art and identify remaining challenges in the field. The identified challenges were formulated as future directions and are summarized in this report, together with an account of the discussion during these two days.

    The workshop explored the following topics Implementing optimal operation using simple control elements, Real time optimisation approach in control structure design and benchmarking, Data driven control configuration selection, and Reconfiguration of control structures. Based on the outcome of the discussion, a group of participants proposed an invited session for the 2018 IFAC AdChem Symposium, which has been accepted at the time of the publication of this report and consists of 6 papers addressing challenges discussed during the workshop.

  • 16.
    Castaño Arranz, Miguel
    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.
    Prediction Error based Interaction Measure for Control Configuration Selection in Linear and Nonlinear Systems2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper introduces an interaction measure, which can be applied both to linear and non-linear systems. The measure is based on the prediction error of the structurally reduced model and is denoted Prediction Error Index Array (PEIA). The linear PEIA is constructed as an extension of previous results using the $\mathcal{H}_2$-norm. The non-linear PEIA is an extension for systems represented by a model in the form of Volterra series. Additionally, the paper gives an interpretation of both linear and nonlinear PEIA as the fraction of the power of the output signal which is expressed by the reduced model resulting from  the  control configuration selection. Several examples are used to illustrate and compare the interaction measure with established methodologies, like the relative gain array, participation matrix, and Hankel Interaction Index array.

  • 17.
    Garmabaki, Amir
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Lindström, John
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Software Fault Detection in Control Systems2017Ingår i: Risk, Reliability and Safety: Innovating Theory and Practice - Proceedings of the 26th European Safety and Reliability Conference, ESREL 2016 / [ed] Walls L.,Revie M.,Bedford T, CRC Press, 2017, s. 2006-2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Fault detection in the software of control systems is a difficult task. In largely interconnected systems, not only the individual performance of one channel, but also its interaction with other components, must be considered. In this conceptual paper, we outline a new maintenance concept for the detection of software faults in control systems. The concept includes two approaches, morning gymnastics test and envelope analysis. The morning gymnastics test generates data for a baseline of the current operational abilities in contrast to the specified abilities and should be applied when feasible in continuous production systems. The test integrates historical and new sets of data to track degradation trends. Envelope analysis can be performed to detect operational anomalies and is based on subsequent deep analysis to distinguish software and hardware faults from each other. By using the envelope analysis it is possible to identify failures and disturbances affecting the control system. Thus, the proposed maintenance concept may facilitate detection and identification of potential failures in critical automated system.

  • 18.
    Kadhim, Ali
    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.
    Castaño Arranz, Miguel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Dynamic Relative Gain Array Estimation using Local Polynomial Approximation Approach2016Ingår i: Modeling, Identification and Control, ISSN 0332-7353, E-ISSN 1890-1328, Vol. 37, nr 4, s. 247-259Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This article presents a procedure that utilizes the local polynomial approximation approach in the estimation of the Dynamic Relative Gain Array (DRGA) matrix and its uncertainty bounds for weakly nonlinear systems. This procedure offers enhanced frequency resolution and noise reduction when random excitation is used. It also allows separation of nonlinear distortions with shorter measuring time when multisine excitation is imposed. The procedure is illustrated using the well-known quadruple tank process as a case study in simulation and in real life. Besides, a comparison with the pairing results of the static RGA, nonlinear RGA and DRGA based on linearized quadruple tank model for different simulation cases is performed.

  • 19.
    Kadhim, Ali
    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.
    Arranz, Miguel Castano
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Dynamic Relative Gain Array Estimation using Local Polynomial Approximation Approach2016Ingår i: Model, Identificationand Control, ISSN 1890-1328, Vol. 37, nr 4, s. 247-259Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This article presents a procedure that utilizes the local polynomial approximation approach in the estimation of the Dynamic Relative Gain Array (DRGA) matrix and its uncertainty bounds for weakly nonlinear systems. This procedure offers enhanced frequency resolution and noise reduction when random excitation is used. It also allows separation of nonlinear distortions with shorter measuring time when multisine excitation is imposed. The procedure is illustrated using the well-known quadruple tank process as a case study in simulation and in real life. Besides, a comparison with the pairing results of the static RGA, nonlinear RGA and DRGA based on linearized quadruple tank model for different simulation cases is performed.

  • 20.
    Cancila, Daniela
    et al.
    CEA France.
    Nuzzo, Valeria
    ECE France.
    Stoycheva, Milena
    University of Trento, Italy.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Asplund, Fredrik
    KTH Royal Institute of Technology.
    Torngren, Martin
    KTH Royal Institute of Technology.
    Experiences and reflections on three years of CPS Summer schools within EIT Digital2016Ingår i: WESE '16: Proceedings of the 2016 Workshop on Embedded and Cyber-Physical Systems Education, New York: ACM Digital Library, 2016, artikel-id 7Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article provides an overview of current European Commission effort in term of educational innovation to reduce the gap between research and industry which still is a barrier to the economic development. Entrepreneurial innovation & education driving Europe's digital transformation (EIT Digital for short) is an European-based initiative fostering I&E (innovation and entrepreneurship) by integrating education, research and business at different educational levels. For instance in EIT master programmes, students work together with industries and academics to have a faster go-to-market of research results. Summer schools are part of the master programs; three of them have been organised related to CPS (cyber-physical systems), critical infrastructure and, more recently, Industry 4.0. Past and present events are discussed and the experience from these events is reported. It is further analysed how the general setup of the summer school program is affecting the educational aspects and achievement of the intended learning outcomes.

  • 21.
    Hostettler, Roland
    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.
    Lundberg Nordenvaad, Magnus
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Maximum Likelihood Estimation of the Non-Parametric FRF for Pulse-Like Excitations2016Ingår i: IEEE Transactions on Automatic Control, ISSN 0018-9286, E-ISSN 1558-2523, Vol. 61, nr 8, s. 2276-2281Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This technical note introduces the closed form maximum likelihood estimator for estimating the coefficients of the non-parametric frequency response function from system identification experiments. It is assumed that the experiments consist of repeated pulse excitations and that both the excitation and system response are measured which leads to an error-in-variables setting. Monte Carlo simulations indicate that the estimator achieves efficiency at low signal-to-noise ratios with only few measurements. Comparison with the least-squares estimator shows that better, unbiased results are obtained.

  • 22.
    Castaño Arranz, Miguel
    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.
    On the selection of control configurations for uncertain systems using gramian-based Interaction Measures2016Ingår i: Journal of Process Control, ISSN 0959-1524, E-ISSN 1873-2771, Vol. 47, s. 213-225Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    critical step in the control design of industrial processes is the Control Configuration Selection (CCS), where each actuator is associated with a set of measurements which will be used in the calculation of the control action.

    A possible solution to the CCS problem is given by the gramian-based Interaction Measures (IMs), which are derived from nominal process models. This paper introduces the derivation of uncertainty bounds for a gramian-based IM using models with uncertainty described in multiplicative form. An alternative to this model-based approach is presented, where uncertainty bounds are estimated from a tailored experiment.

    In addition, a procedure for robust CCS is introduced. This procedure integrates the calculated uncertainty bounds in the design of the control configuration.

  • 23.
    Birk, Wolfgang
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Ritter, Yvonne
    TWT GmbH Science & Innovation.
    Linder, Nicklas
    TWT GmbH Science & Innovation.
    Odefey, Ulrich
    TWT GmbH Science & Innovation.
    Lingman, Peter
    Optimation AB.
    Chandan, Vikas
    IBM India.
    OPTI-Sim: co-simulation based virtualization of large scale DHC-networks2016Konferensbidrag (Refereegranskat)
  • 24.
    Atta, Khalid
    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.
    Hostettler, Roland
    Department of Electrical Engineering and Automation, Aalto University.
    Johansson, Andreas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Phasor extremum seeking control with adaptive perturbation amplitude2016Ingår i: 2016 IEEE 55th Conference on Decision and Control, CDC 2016, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 7069-7074, artikel-id 7799358Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we propose a perturbation amplitude adaption scheme for phasor extremum seeking control based on the plant's estimated gradient. By using phasor extremum seeking instead of classical extremum seeking, the problem of algebraic loops in the controller formulation is avoided. Furthermore, a stability analysis for the proposed method is provided, which is the first stability analysis for extremum seeking controllers using adaptive amplitudes. The proposed method is illustrated using numerical examples and it is found that changes in optimum can be tracked accurately while the steady-state perturbations can be reduced significantly.

  • 25.
    Birk, Wolfgang
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Dudarenko, Natalia
    Saint-Petersburg National Research University of Information Technologies, Mechanics and Optics.
    Reconfiguration of the air control system of a bark boiler2016Ingår i: IEEE Transactions on Control Systems Technology, ISSN 1063-6536, E-ISSN 1558-0865, Vol. 24, nr 2, s. 565-577Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper the problem of reconfiguration of controllers in the air control system of a bark boiler is addressed. The air control system of a bark boiler is considered as an interconnected multivariable system and the configuration of the controllers is adapted with the perspective to improve the closed loop performance of the system. The paper proposes a generic procedure for the reconfiguration of controllers using a combination of established theories together with rather recently proposed methods. The procedure is applied to a model of the air flow system, which is derived in this study. The results indicate that a significant performance improvement can be achieved by reconfiguring the control system instead of re-design the process. The improvement is quantified through theoretical assessment, simulation studies, and performance assessment of pilot tests at the bark boiler at SCA Obbola Sweden. It can be concluded that the proposed procedure is both efficient and easy to apply.

  • 26.
    Törngren, Martin
    et al.
    Mechatronics/Machine Design, KTH, Stockholm .
    Edin Grimheden, Martin
    Mechatronics/Machine Design, KTH, Stockholm .
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Jonas
    Strategies and considerations in shaping cyber-physical systems education2016Ingår i: ACM SIGBED Review, ISSN 1551-3688, Vol. 14, nr 1, s. 53-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Embedded and Cyber-Physical Systems education faces several challenges as well as opportunities as every-"thing" becomes connected, and as technology development accelerates. Initiatives such as CDIO, as well as several other academic and industry initiatives to create new CPS programs illustrate strong interests and awareness of these challenges. We provide an overview of foreseen educational needs, existing state of the art in education and an analysis of the subject of CPS with the purpose of understanding the implications for education. The investigation points to key issues in curriculum design regarding balancing depth and breadth, theory and practices, academic and industrial needs, and core technical skills with complementary skills. Curricula in CPS could, if the right balance is achieved, educate CPS engineers of the future that are "ready to engineer". We conclude by synthesizing high level guidelines in terms of strategies and considerations for CPS curriculum development.

  • 27.
    Kadhim, Ali
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Castaño Arranz, Miguel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    System Uncertainty Effect on Optimal Control Configuration Selection2016Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    An approach to investigate the effect of system uncertainty on the optimal controlconfiguration selection in multivariable systems is proposed. An optimal control configuration,i.e the configuration which best agrees with input-output pairing rules according to certaininteraction measure (IM) can be obtained automatically by formulating the control configurationselection as a Transportation Problem (TP). The proposed approach then checks whetherthis optimal control configuration is valid for given system uncertainties or if a change in theconguration could be expected.

  • 28.
    Birk, Wolfgang
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Atta, Khalid
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Towards Autonomous Synthesis of Building Substation Control Loops2016Ingår i: IEEE International Conference on Smart Grid Communications (SmartGridComm) 2016, Piscataway, NJ, 2016, s. 38-44, artikel-id 7778735Konferensbidrag (Refereegranskat)
    Abstract [en]

    The main contribution of this paper is to study the feasibility of an automated approach to the assessment and synthesis of control loops in substations of a district heating and cooling system. The low-level controllers in substation are usually PID-type controllers and can not easily be changed. Moreover, the tuning of these controllers is often done in an ad-hoc manner and remains in the initial tuning despite changes in the substation over their operational life. Consequently, insufficient control performance due to false tuning can be misinterpreted as a hardware issue and lead to unnecessary replacement of parts.

    In order to solve this problem, the paper proposes an approach to assess the control loop performance based on logged data from substations, and to subsequently tune the current substation controllers, when no hardware issues are detected. The approach is applied to a well-known building substation model in simulation, which indicates that the approach is feasible.

    Analysis of acquired data from a number of substations in the DHC system of Luleå Energi AB, provides evidence for the problem and how the approach can be applied in its future implementation. Moreover, a number of challenges and future work are indicated.

  • 29.
    Kleyko, Denis
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Hostettler, Roland
    Department of Electrical Engineering and Automation, Aalto University.
    Lyamin, Nikita
    School of Information Technology, Halmstad University.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Wiklund, Urban
    Department of Biomedical Engineering and Informatics, Umeå University.
    Osipov, Evgeny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Vehicle Classification using Road Side Sensors and Feature-free Data Smashing Approach2016Ingår i: 2016 IEEE 19th International Conference on Intelligent Transportation Systems (ITSC 2016), Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 1988-1993, artikel-id 7795877Konferensbidrag (Refereegranskat)
    Abstract [en]

    The main contribution of this paper is a study of the applicability of data smashing – a recently proposed data mining method – for vehicle classification according to the “Nordic system for intelligent classification of vehicles” standard, using measurements of road surface vibrations and magnetic field disturbances caused by passing vehicles. The main advantage of the studied classification approach is that it, in contrast to the most of traditional machine learning algorithms, does not require the extraction of features from raw signals. The proposed classification approach was evaluated on a large dataset consisting of signals from 3074 vehicles. Hence, a good estimate of the actual classification rate was obtained. The performance was compared to the previously reported results on the same problem for logistic regression. Our results show the potential trade-off between classification accuracy and classification method’s development efforts could be achieved.

  • 30.
    Karim, Ramin
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Larsson-Kråik, Per-Olof
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Cloud-based emaintenance solutions for condition-based maintenance of wheels in heavy haul operation2015Ingår i: 11th International Heavy Haul Conference, (IHHA 2015): 21 – 24 June 2015, Perth, Australia, International Heavy Haul Association , 2015Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Swedish ore line, began in 1898 and was completed and operational by 1902. The line was later electrified and remains so to this day. A study on wheel-rail interaction, to optimize wheel and rail profiles on the Malmbanan and Ofoten lines states that there is a need to develop and apply limit values for the allowable length of single and multiple cracks on wheels. Herein, all stakeholders in the railway organization have to be involved. Provisioning of an integrated decision support system for track and vehicle contributes to increased efficiency and improved effectiveness of the maintenance process, which in turn enables achievement of business excellence. However, an integrated decision support process for maintenance is highly dependent on appropriate information logistics which enables information provisioning to various maintenance stakeholders. One emerging approach for development of eMaintenance solutions is utilization of cloud-based technologies. Cloud-based eMaintenance solutions promises smooth information logistics for maintenance decision support. Hence, the purpose of this paper is to propose an approach for condition-based maintenance decision-making relating to railway vehicle wheels, based on a cloud-based eMaintenance solution. The paper also demonstrates how the proposed approach can be implemented for estimation of Remaining Useful Life (RUL) of railway vehicle wheels.

  • 31.
    Kleyko, Denis
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Hostettler, Roland
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system. Luleå tekniska universitet, Institutionen för system- och rymdteknik, CDT.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Osipov, Evgeny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Comparison of Machine Learning Techniques for Vehicle Classification using Road Side Sensors2015Ingår i: Proceedings of the 2015 IEEE 18th International Conference on Intelligent Transportation Systems: Las Palmas, 15-18 Sept. 2015, Piscataway, NJ: IEEE Communications Society, 2015, s. 572-577, artikel-id 7313192Konferensbidrag (Refereegranskat)
    Abstract [en]

    The main contribution of this paper is a comparison of different machine learning algorithms for vehicle classification according to the "Nordic system for intelligent classification of vehicles" standard using measurements of road surface vibrations and magnetic field disturbances caused by vehicles. The algorithms considered are logistic regression, neural networks, and support vector machines. They are evaluated on a large dataset, consisting of 3074 samples and hence, a good estimate of the actual classification rate is obtained. The results show that for the considered classification problem logistic regression is the best choice with an overall classification rate of 93.4%.

  • 32.
    Castano, Miguel
    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.
    Asplund, Petter
    Optimation AB.
    Control configuration selection for integrating processes using graphs2015Ingår i: 2015 IEEE International Conference on Control Applications (CCA 2015): Sydney, Australia, September 21-23, Piscataway, NJ: IEEE Communications Society, 2015, s. 1606-1611, artikel-id 7320839Konferensbidrag (Refereegranskat)
    Abstract [en]

    Recently, methods for Control Configuration Selection (CCS) using weighted graphs have been introduced. These methods were integrated in a software tool which allows systematic CCS in industry processes by choosing a simplified model with a reduced structure on which control will be based. This paper addresses the extension of these graph-based methods to be applied to integrating systems, which often appear in industry processes, e.g. at storage vessels. The extension is based on restricting the analysis to a set of frequencies of interest which omits the infinite DC-gain. The results are validated and illustrated using a real-life case, namely the secondary heating system of a pulp & paper mill.

  • 33.
    Castaño, Miguel
    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.
    Estimation of Gramian-Based Interaction Measures for Weakly Nonlinear Systems2015Ingår i: 2015 European Control Conference (ECC): Linz, 15-17 July 2015, Piscataway, NJ: IEEE Communications Society, 2015, s. 2438-2443Konferensbidrag (Refereegranskat)
    Abstract [en]

    A critical step in the control design of industrial processes is the Control Configuration Selection (CCS), where each actuator is grouped with a set of measurements to be used in the computation of its control action.Tools for CCS include gramian-based Interaction Measures (IMs), initially defined for linear systems. Since a trending research topic is the derivation of IMs for non-linear systems, a decision of the designer is therefore the approach to the problem in the linear or non-linear framework. For this end, a method is discussed that determines the degree of nonlinearity of a system based on a specially tailored experiment, and thus enables the selection of the correct framework for the analysis. The novelty is in the estimation of two gramian-based IMs with confidence bounds from the tailored experiment which is applicable if the process is revealed to be weakly non-linear. If the process is found to be strongly non-linear, then alternative approaches for the interaction analysis have to be considered.

  • 34.
    Hostettler, Roland
    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.
    Nordenvaad, Magnus Lundberg
    Joint Vehicle Trajectory and Model Parameter Estimation using Road Side Sensors2015Ingår i: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 15, nr 9, s. 5075-5086Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This article shows how a particle smoother based system identification method can be applied for estimating the trajectory of road vehicles. As sensors, a combination of an accelerometer measuring the road surface vibrations and a magnetometer measuring magnetic disturbances mounted on the side of the road are considered. First, sensor models describing the measurements of the two sensors are introduced. It is shown that these depend on unknown, static parameters that have to be considered in the estimation. Second, the sensor models are combined with a two-dimensional constant velocity motion model. Third, the system identification algorithm is introduced which iteratively runs a Rao-Blackwellized particle smoother to estimate the vehicle trajectory followed by an expectation-maximization step to estimate the parameters. Finally, the method is applied to both simulation and measurement data. It is found that the method works well in general and some issues when real data is considered are identified as future work.

  • 35.
    Kadhim, Ali
    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.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Relative Gain Array Estimation Based on Non-parametric Process Identification for Uncertain Systems2015Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Since the introduction of the Relative Gain Array (RGA) by Bristol in 1966, it has become awidely used practical tool for solving the input-output pairing problems in decentralized control. In order to remove the dependency of this tool on a parametric description and accurate knowledge of a nominal model, this work proposes a method to estimate the RGA directly from a non-parametric frequency response matrix (FRM) derived from a frequency domain system identification approach. The proposed method reduces the influence of model uncertainties on the calculation of the RGA and derives the RGA at frequencies of interest. The results are exemplified using a 2x3 LTI systems and a 2x2 uncertain system.

  • 36.
    Kadhim, Ali
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Castano, Miguel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Relative Gain Array of Weakly Nonlinear Systems using a Nonparametric Identification Approach2015Ingår i: 2015 IEEE International Conference on Control Applications (CCA 2015): Sydney, Australia, September 21-23, Piscataway, NJ: IEEE Communications Society, 2015, s. 1612-1617, artikel-id 7320840Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article presents a procedure to estimate the relative gain array (RGA) matrix for weakly nonlinear systems by means of nonparametric identification of the frequency response matrix (FRM). Specifically, the best linear approximation of nonlinear systems and the covariance of the nonlinear distortions are used in the relative gain array estimation. For the estimation neither process model nor model structure need to be known which is an advantage over methods that require accurate knowledge of a parametric process model. The proposed approach is compared with the original RGA and a nonlinear RGA calculation using the well-known quadruple tank process as a case

  • 37.
    Kadhim, Ali
    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.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Relative Gain Array Variation for Norm Bounded Uncertain Systems2015Ingår i: IEEE 54th Annual Conference on Decision and Control (CDC): Osaka, Japan, 15-18 Dec. 2015, Piscataway, NJ: IEEE Communications Society, 2015, s. 5959-5965, artikel-id 7403156Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article proposes computationally tractable, easyto expand and tight relative gain variation bound for uncertain systems. The proposed bound is a further development of previous work, which is summarized anddiscussed. Using several examples, the new method is compared with previous results and the advantages are highlighted. The prediction of sign changes in relative gain array elements due to uncertainties is important for pairing decisions. Based on the proposed bound,a method for the prediction of the uncertainty levels which render sign changes is suggested. The prediction method is currently limited to certain classes of systems.In this prediction method neither prior knowledge of the uncertainty nor numerous calculations are needed.

  • 38.
    Birk, Wolfgang
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Castaño, Miguel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik.
    Johansson, Andreas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    An Application Software For Visualization and Control Configuration Selection of Interconnected Processes2014Ingår i: Control Engineering Practice, ISSN 0967-0661, E-ISSN 1873-6939, Vol. 26, s. 188-200Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a new application software for control conguration selection of interconnected industrial processes,called ProMoVis. Moreover, ProMoVis is able to visualize process models and process layout at the physical leveltogether with the control system dynamics. The software consists of a builder part where the visual representationof the interconnected process is created and an analyzer part where the process is analyzed using dierent controlconguration selection tools.The conceptual idea of the software is presented and the subsequent design and implementation of ProMoVis isdiscussed. The implemented analysis methods are briey described including their usage and implementation aspects.The use of ProMoVis is demonstrated by an application study on the stock preparation process at SCA Obbola AB,Sweden. The results of this study are compared with the currently used control strategy.The study indicates that ProMoVis introduces a systematic and comprehensive way to perform control congurationselection. ProMoVis has been released under the Apache Open Source license.

  • 39.
    Dadhich, Siddharth
    et al.
    Luleå tekniska universitet.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Analysis and control of an extended Quadruple tank process2014Ingår i: 2014 European Control Conference (ECC), June 24-27, 2014. Strasbourg, France, Piscataway, NJ: IEEE Communications Society, 2014, s. 838-843, artikel-id 6862290Konferensbidrag (Refereegranskat)
    Abstract [en]

    An extension to the standard Quadruple tank process is proposed and analyzed. It is shown that the extended setup provides an improved platform for experimental and educational studies of MIMO control systems. Based on dynamic models for the process a control configuration selection is performed and both decentralized and decoupling control schemes are designed and tested. Moreover sparse IMC controllers have been evaluated against a decentralized control scheme for improvement in the stochastic performance. It is shown how a performance assessment method based on the FCOR algorithm can be used to find the optimal tuning of the IMC controller. It can be concluded that the proposed extension to the quadruple tank process is useful for benchmark and educational purposes.

  • 40.
    Kadhim, Ali
    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.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Calculation of Relative Gain Array Based on Nonparametric Process Identification: A Frequency Domain Approach2014Konferensbidrag (Övrigt vetenskapligt)
  • 41.
    Wahlström, Niklas
    et al.
    Linköpings universitet.
    Hostettler, Roland
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Fredrik
    Linköpings universitet.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Classification of driving direction in traffic surveillance using magnetometers2014Ingår i: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 15, nr 4, s. 1405-1418Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Traffic monitoring using low-cost two-axis magnetometers is considered. Although detection of metallic vehicles is rather easy, detecting the driving direction is more challenging. We propose a simple algorithm based on a nonlinear transformation of the measurements, which is simple to implement in embedded hardware. A theoretical justification is provided, and the statistical properties of the test statistic are presented in closed form. The method is compared with the standard likelihood ratio test on both simulated data and real data from field tests, where very high detection rates are reported, despite the presence of sensor saturation, measurement noise, and near-field effects of the magnetic field.

  • 42.
    Höhn, Patrick
    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.
    Energy Optimization of a High Consistency Refiner Process2014Konferensbidrag (Övrigt vetenskapligt)
  • 43.
    Höhn, Patrick
    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.
    Energy Optimization of a High Consistency Refiner Process2014Ingår i: 2014 IEEE International Conference on Control Applications (CCA 2014): Juan Les Antibes, France, 8 -10 October 2014, Piscataway, NJ: IEEE Communications Society, 2014, s. 197-203Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a concept for energy optimization dealing with high consistency (HC) refining processes in the pulp and paper industry. Models for the outlet consistency and Gurley number used in the optimization are briefly described. The specific energy is used as manipulated variable. Additionally, the inlet consistency can be adjusted to a fixed value. While keeping the energy consumption as low as possible, it is still attempted to keep outlet consistency and Gurley number close to its desired value. The optimization uses a cost function with quadratic terms. An explicit solution for the optimization problem is derived. Additionally, the results are compared with findings from numerical optimization using a global search algorithm and an interior point method. Results presented are consistent with each other and indicate potential for energy savings.

  • 44.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Intelligent industrial Processes: Automatic Control Perspective2014Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Intelligent Industrial Processes is an area of excellence in research and innovation at Luleå University of Technology (LTU), which was formed to promote multi-disciplinary research and innovation relating to Process Industrial Automation, also referred to as ProcessIT. LTU has a strong track record of research in close collaboration with process industries, where research results have often found their way into products and services strengthening the industries position on the global market.For this area of excellence a road mapping study with respect to Automatic Control research was conducted and is summarized in this white paper. The study shows that current research activities in Automatic Control are very relevant to Intelligent Industrial Processes, dealing with techniques for process understanding (modeling), design and implementation of control systems, and process monitoring, only to mention some.It is concluded that the design and establishment of an Open Research and Innovation Platform is essential for collaborative and multi-disciplinary research in the area. Such a software platform will enable industry partners to more efficiently work with their industrial processes and that in close collaboration with researchers and engineering businesses. At the same time researchers and innovators will have the opportunity to test and validate their results and innovations on real-life cases, enabling a swift exploitation of results. Some key principles for this software platform are the open source, open data and open innovation principles that need to be captured in the platform.The results of that study suggest initial automatic control research activities and a time line for stepping stones towards a full scale implementation of an Open Research and Innovation Platform by 2030.

  • 45.
    Kadhim, Ali
    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.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Relative gain array estimation based on non-parametric frequency domain system identification2014Konferensbidrag (Refereegranskat)
  • 46.
    Kadhim, Ali
    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.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Relative Gain Array Estimation Based on Non-Parametric Frequency Domain System Identification2014Ingår i: 2014 IEEE International Conference on Control Applications (CCA 2014): Juan Les Antibes, France, 8 -10 October 2014, Piscataway, NJ: IEEE Communications Society, 2014, s. 110-115Konferensbidrag (Refereegranskat)
    Abstract [en]

    Since the introduction of the Relative Gain Array (RGA) by Bristol in 1966, it has received a high level of attention as a practical tool for solving the input-output pairing problem in decentralized control. Moreover, many extensions have been proposed like e.g. for the dynamic case and non-square system matrices. Recently, extensions that provide tools for uncertain parametric process models were suggested. In order to removethe dependency of these tools on a parametric description and accurate knowledge of a nominal model this paper proposes a method to calculate the RGA directly from a non-parametric frequency response matrix (FRM), derived from frequency domain system identification approach. The proposed method reduces the influence of model uncertainties on the calculation of the RGA and derives the RGA at frequencies of interest. Using Monte-Carlo principles, the variance of the estimated RGA is derived and compared with recently proposed methods. The results are exemplified on 2 by 2, 2 by 3 and 3 by 3 systems. It concluded that the proposed methods performs well and robust, while simplifying the estimation of the RGA.

  • 47.
    Castaño, Miguel
    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.
    Asplund, Petter
    Optimation AB.
    Rönnberg, Johan Karlsson
    K Algorithm Design.
    Systematic Control Configuration Selection of Secondary Heating Systems: A Case Study2014Konferensbidrag (Övrigt vetenskapligt)
  • 48.
    Castaño, Miguel
    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.
    Asplund, Petter
    Optimation AB.
    Rönnberg, Johan Karlsson
    K Algorithm Design.
    Systematic Control Configuration Selection of Secondary Heating Systems: A Case Study2014Konferensbidrag (Övrigt vetenskapligt)
  • 49.
    Hostettler, Roland
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nordenvaad, Magnus Lundberg
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    The pavement as a waveguide: modeling, system identification, and parameter estimation2014Ingår i: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 63, nr 8, s. 2052-2063Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents modeling of wave propagation in pavements from a system identification point of view. First, a model based on the physical structure is derived. Second, experiment design and evaluation are discussed and maximum-likelihood estimators for estimating the model parameters are introduced, assuming an error-in-variables setting. Finally, the proposed methods are applied to measurement data from two experiments under varying environmental conditions. It is found that the proposed methods can be used to estimate the dispersion curves of the considered waveguide and the results can be used for further analysis

  • 50.
    Kadhim, Ali
    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.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Evaluation of vehicle tracking for traffic monitoring based on road surface mounted magnetic sensors2013Ingår i: The Third IFAC Symposium on Telematics Applications (TA 2013)Applications: November 11‒13, 2013, Yonsei University, Seoul, Korea / [ed] Jang-Won Lee, Red Hook, NY: Curran Associates, Inc., 2013, s. 13-18Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this work is to evaluate a vehicle tracking scheme as a means of monitoring traffic on roads. The scheme can be used as a component in a traffic monitoring system which can provide traffic management systems and road maintainers with traffic information. Vehicle tracking is achieved by determining vehicle position, velocity and magnetic moment using a nonlinear weighted least squares method (NWLS) on readings from two 3-axes magnetic sensors.The tracking was performed both in simulation and in real life. The traffic monitoring system is composed of two adjacently glue attached wireless sensor nodes, which are placed at a distance of 1 m along the road. A potential misalignment of the sensors due to placement errors is analysed in simulation and addressed.

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