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  • 151.
    Dadhich, Siddharth
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Sandin, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Bodin, Ulf
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Predicting bucket-filling control actions of a wheel-loader operator using aneural network ensemble2018Ingår i: 2018 International Joint Conference on Neural Networks (IJCNN), Piscataway, NJ: IEEE, 2018, artikel-id 8489388Konferensbidrag (Refereegranskat)
    Abstract [en]

    Automatic bucket filling is an open problem since three decades. In this paper, we address this problem with supervised machine learning using data collected from manual operation. The range-normalized actuations of lift joystick, tilt joystick and throttle pedal are predicted using information from sensors on the machine and the prediction errors are quantified. We apply linear regression, k-nearest neighbors, neural networks, regression trees and ensemble methods and find that an ensemble of neural networks results in the most accurate predictions. The prediction root-mean-square-error (RMSE) of the lift action exceeds that of the tilt and throttle actions, and we obtain an RMSE below 0.2 for complete bucket fillings after training with as little as 135 bucket filling examples

  • 152.
    Dadhich, Siddharth
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Sandin, Fredrik
    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, Signaler och system.
    Martinsson, Torbjörn
    Volvo CE, Bolindervägen 5, 63185 Eskilstuna, Sweden.
    Field test of neural-network based automatic bucket-filling algorithm for wheel-loaders2019Ingår i: Automation in Construction, ISSN 0926-5805, E-ISSN 1872-7891, Vol. 97, s. 1-12Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Automation of earth-moving industries (construction, mining and quarry) require automatic bucket-filling algorithms for efficient operation of front-end loaders. Autonomous bucket-filling is an open problem since three decades due to difficulties in developing useful earth models (soil, gravel and rock) for automatic control. Operators make use of vision, sound and vestibular feedback to perform the bucket-filling operation with high productivity and fuel efficiency. In this paper, field experiments with a small time-delayed neural network (TDNN) implemented in the bucket control-loop of a Volvo L180H front-end loader filling medium coarse gravel are presented. The total delay time parameter of the TDNN is found to be an important hyperparameter due to the variable delay present in the hydraulics of the wheel-loader. The TDNN network successfully performs the bucket-filling operation after an initial period (100 examples) of imitation learning from an expert operator. The demonstrated solution show only 26% longer bucket-filling time, an improvement over manual tele-operation performance.

  • 153.
    Dai, William
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Riliskis, Laurynas
    Vyatkin, Valeriy
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Osipov, Evgeny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    A Configurable Cloud-Based Testing Infrastructure for Interoperable Distributed Automation Systems2015Ingår i: IECON 2014: 40th Annual Conference of the IEEE Industrial Electronics Society, Dallas, TX, USA , Oct. 29 2014-Nov. 1 2014, Piscataway, NJ: IEEE Communications Society, 2015, s. 2492-2498Konferensbidrag (Refereegranskat)
    Abstract [en]

    The interoperability between various automation systems is considered as one of the major character of future automation systems. Service-oriented Architecture is a possible interoperability enabler between legacy and future automation systems. In order to prove the interoperability between those systems, a verification framework is essential. This paper proposes a configurable cloud-based validation environment for interoperability tests between various distributed automation systems. The testing framework is implemented in a multi-layer structure which provides automated closed-loop testing from the protocol level to the system level. The testing infrastructure is also capable for simulating automation systems as well as wireless sensor networks in the cloud. Test cases could be automatically generated and executed by the framework.

  • 154.
    Daroui, Danesh
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Efficient PEEC-based solver for complex electromagnetic problems in power electronics2012Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The research presented in this thesis discusses an electromagnetic (EM) analysis tool which is based on the partial element equivalent circuit (PEEC) method and is appropriate for combined EM and circuit simulations especially power electronics applications. EM analysis is important to ensure that a system will not affect the correct operation of other devices nor cause interference between various electrical systems. In power electronic applications, the increased switching speed can cause voltage overshoots, unbalanced current share between semiconductor modules, and unwanted resonances. Therefore, EM analysis should be carried out to perform design optimizations in order to minimize unwanted effects of high frequencies. The solver developed in this work is an appropriate solution to address the needs of EM analysis in general and power electronics in particular. The conducted research consists of performance acceleration and implementation of the solver, and verification of the simulation results by means of measurements. This work was done in two major phases.In the first phase, the solver was accelerated to optimize its performance when quasi-static (R,Lp,C)PEEC as well as full-wave (R,Lp,C,tau)PEEC simulations were carried out. The main optimizations were based on exploiting parallelism and high performance computing to solve very large problems and non-uniform mesh, which was helpful in simulating skin- and proximity effects while keeping the problem size to a minimum. The presented results and comparisons with the measurements confirmed that non-uniform mesh helped in accurately simulating large bus bar models and correctly predicting system resonances when the size of the problem was minimized. On-the-fly calculation was also developed to reduce memory usage, while increasing solution time.The second phase consists of methods to increase the performance of the solver while including some levels of approximations. In this phase sparsification techniques were used to convert a dense PEEC system into a sparse system. The sparsification was done by calculating the reluctance matrix, which can be sparsified by maintaining the accuracy at the desired level, because of the locality and the shielding effect of the reluctance matrix. Efficient algorithms were developed to perform sparse matrix-matrix multiplication and assemble the sparse coefficient matrix in a row-by-row manner to reduce the peak memory usage. The sparse system was then solved using both sparse direct and iterative solvers with proper preconditioning. The acquired results from the sparse direct solution confirmed that the memory consumption and solution time were reduced by orders of magnitude and by a factor 3 to 5. Moreover, the Schur complement was used together with the iterative approach, making it possible to solve large problems within a few iterations by preconditioning the system, and using less memory and lower computational complexity. Bus bars used in two types of power frequency converters manufactured by ABB were modelled and analysed with the developed PEEC-based solver in this research, and the simulations and measurements agreed very well. Results of simulations also led to improvement in the physical design of the bars, which reduced the inductance of the layout.With the accelerated solver, it is now possible to solve very large and complex problems on conventional computer systems, which was not possible before. This provides new possibilities to study real-world problems which are typically large in size and have complex structures.

  • 155.
    Daroui, Danesh
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Implementation and optimization of partial element equivalent circuit-based solver2010Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The Partial Element Equivalent Circuit (PEEC) method is an integral equation based full-wave approach to solve combined circuit and electromagnetic problems in the time and frequency domain. Using PEEC, an electromagnetic problem is transferred to the circuit domain and then solved using circuit theory which gives PEEC a high flexibility to be used in combined electromagnetic and circuit modeling problems. Thus, the method can be applied to different classes of problems, for example power electronics systems and antenna simulation to ensure the functionality of the system and also comply with electromagnetic compatibility (EMC) regulations. Other methods, like Finite Element Method or Finite Difference Time Domain Methods, are also used for electromagnetic analysis and an optimal computer implementation is needed to be able to handle such problems within a reasonable time and at certain accuracy.This work presents the development and optimization of a PEEC-based software on different computing platforms. The aim of the acceleration is to be able to solve problems using the PEEC method as fast as possible with optimum memory usage on a regular computer system. The PEEC-based solver has been developed for desktop machines using the GMM++ linear algebra package. This implementation was optimized by improving the code, to use more efficient libraries and adapt the program to run on powerful machines. Another part of this optimization process was to implement smart algorithms like non-uniform meshing and on-the-fly calculations for the partial elements. Though, the code has been recently enhanced to take advantage of the multicore hardware by replacing old library with Intel Math Kernel Library (MKL) in order to take advantage of several processors which exist on typical computer system.To be able to solve very large problems which for example needs several hundred gigabytes of memory, the code was also ported into parallel computer systems. The parallel PEEC solver is compatible with the distributed memory architecture and thus, is scalable by using a set of computing units which collaborate to solve a problem. Hence, by allocating enough number of processors and amount of memory, the load of the solution will be distributed over different elements. Consequently, one of the challenging parts of these kinds of distributed computations is to distribute data, using a balanced manner to minimize data movement between nodes which will slow down the running process. The balanced distribution of data was ensured, by using Basic Linear Algebra Subprograms (BLAS) and Scalable Linear Algebra Package (ScaLAPACK) libraries to handle linear algebraic calculations in the parallel solver. Using these tools, the matrix elements are dispensed according to the block-cyclic decomposition scheme which guarantees that data is uniformly assigned to each computing node. Several test cases have been run, in order to benchmark the computer implementation. On account of the applied optimization techniques, the sequential solver needs less memory and performs the solution remarkably faster than before. As an example, high frequency simulations can now be run now with the optimized code, within shorter time and with less memory usage, by having very light mesh, using non-uniform meshing. According to the benchmarking results of the parallel solver, the results of these tests did agree very well with the physical measurements and also showed an acceptable speed-up factor as number of processors as well as size of the problems grew in the parallel version of the solver. The robustness of the parallel solver was verified by stressing the code with the largest test case which was a problem with more than 250 000 unknowns. Further steps of the acceleration would be focusing on the smarter algorithms as well as numerical methods like Fast Multipole Method (FMM), using iterative solvers instead of direct solvers and QR Decomposition. An important issue which needs to be considered is the approximations which will appear in the results as a consequence of usage of such techniques like numerical instabilities and loss of accuracy.

  • 156.
    Daroui, Danesh
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Combined circuit and electromagnetic modelling on multi-core platforms2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    Computer simulation techniques are widely used in various fields to design and verify the functionality, performance, quality, or safety of a product. In electrical systems, with increasing operational frequencies, capacitive and inductive couplings between parts in an embedded system might have to be taken into account. Therefore, traditional circuit analysis are not sufficient for such problems. Hence, other simulation approaches such as Partial Element Equivalent Circuit (PEEC), Method of Moments, and Finite Element Methods, and other have been developed to fulfill this need. By using the PEEC method, the simulation of the functionality of an electrical device can be combined with an electromagnetic analysis. Thus, the method has been widely used in combined circuit and electromagnetic modeling on problems in different classes in power electronic industry and antenna design. The main aim of this paper is to demonstrate how multi-core systems can contribute to improve the performance of a PEEC-based electromagnetic simulation tool and to show that the improvements make it possible to solve larger and more complex problems in a reasonable time.A PEEC-based solver has been developed at Luleå University of Technology. The kernel of the solver has been implemented in C++ and is designed to run on different desktop platforms and operating systems. It is known that in the PEEC formulations there are large, dense, and in many cases non-symmetric matrices which increase the computational costs. Hence, using an efficient and robust library as well as support for the recently advanced hardware, is vital and will highly affect the performance of the solver.

  • 157.
    Daroui, Danesh
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Efficient PEEC-based simulations using reluctance method for power electronic applications2012Ingår i: Applied Computational Electromagnetics Society Journal, ISSN 1054-4887, Vol. 27, nr 10, s. 830-841Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a partial element equivalent circuit (PEEC)-based solver that has been accelerated to exploit the massively parallel structure of graphics processing unit (GPU) technology, in order to employ a reluctance-based method in an efficient way. A grouping algorithm is also presented which makes reluctance calculation efficient, suitable for GPUs, and feasible even for very large problems. It has been shown that by using the reluctance method, the coefficient matrix in the system equation can be safely sparsified whilst the required accuracy is maintained. Because the calculation of the reluctance matrix includes matrix inversion, which is a task with high computational complexity, GPUs as cooperative units are utilized to reduce computational costs by taking advantage of parallelism. Two test models have been simulated and analyzed to benchmark the solver, and the results have been compared with the previously developed solver. Furthermore, analyzing the results reveals that the reluctance method makes it possible to use a considerably sparser system and thereby solve large problems by decreasing the memory demands and the solution time. It is also proven that the solution is reliable and accurate, whereas the problem has become noticeably smaller.

  • 158.
    Daroui, Danesh
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Iterative PEEC-based power electronic systems simulations using reluctance and regularization techniques2012Ingår i: EMC Europe 2012: International Symposium on Electromagnetic Compatibillity, September 15-21, Rome, Italy, 2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a method to deal with the ill-posed and rank-deficient linear systems arising from sparsified partial element equivalent circuit-based electromagnetic simulations via a reluctance method. Since conventional, direct methods, cannot be used to solve these kind of problems, regularization techniques need to be employed. Among various regularization techniques, a least square-based method entitled LSQR is utilized to solve the rank-deficient problems. The proposed method is specially proper for the models where capacitive couplings can be neglected, since magnetic field is the dominating factor, like problems within power electronics. The correctness of the presented PEEC-based solver is ensured by studying bus bar models which are a part of frequency converters with application in power electronics.

  • 159. Daroui, Danesh
    et al.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Parallel implementations of the PEEC method2010Ingår i: Applied Computational Electromagnetics Society Journal, ISSN 1054-4887, Vol. 25, nr 5, s. 410-422Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents the first parallel implementation of a partial element equivalent circuit (PEEC) based electromagnetic modelling code suitable for solving general electromagnetic problems. The parallelization is based on the GMM++ and ScaLAPACK packages which are cross-platform libraries available for major operating systems. The parallel PEEC solver has been tested on several high performance computer systems. Large structures containing over 250 000 unknown current and voltage basis functions were successfully analyzed for the first time with a general PEEC-solver. The numerical examples are of orthogonal type, studied both in the time and frequency domain, for which memory, performance, and speed-up results are presented.

  • 160.
    Daroui, Danesh
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    PEEC-based Simulations Using Iterative Method and Regularization Technique for Power Electronic Applications2014Ingår i: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187X, Vol. 56, nr 6, s. 1448-1456Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The partial element equivalent circuit (PEEC) method has been widely used in different industrial and scientific fields for electromagnetic analysis. PEEC-based solvers have been optimized and accelerated in order to be able to solve larger and more complex problems that arise in industry. In power electronic system simulations, PEEC models are often simplified by neglecting electric field couplings and using quasi-static model. The simplified system can be further accelerated using reluctance technique and then sparsified up to high levels without degrading the accuracy of the solution. In previous work, the sparse system was solved using sparse direct solution, while in this study, an iterative approach is employed which resulted in lower time complexity of the solution. However, since matrices achieved from PEEC equations are severely ill-conditioned, regularization techniques need to be applied to avoid numerical instabilities. The regularization is done mathematically and can be interpreted as adding a frequency-dependent pseudocapacitor to each node in the PEEC model. Because the pseudocapacitors are frequency dependent, hence frequencies close to dc are not covered in this study and have left as future work. The new sparse and regularized system can then be solved using a Schur complement technique together with iterative solvers with a novel preconditioning approach.

  • 161.
    Daroui, Danesh
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Performance analysis of parallel non-orthogonal PEEC-based solver for EMC applications2012Ingår i: Progress in Electromagnetics Research B, ISSN 1937-6472, E-ISSN 1937-6472, Vol. 41, s. 77-100Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A parallel implementation of a quasi-static Partial Element Equivalent Circuit (PEEC)-based solver that can handle electromagnetic problems with non-orthogonal structures is presented in this paper. The solver has been written in C++ and employs GMM++ and ScaLAPACK computational libraries to make the solver fast, efficient, and adaptable to current parallel computer systems. The parallel PEEC-based solver has been tested and studied on high performance computing clusters and the correctness of the solver has been verified by doing comparisons between results from orthogonal routines and also another type of electromagnetic solver, namely FEKO. Two non-orthogonal numerical test cases have been analysed in the time and frequency domain. The results are given for solution time and memory consumption while bottlenecks are pointed out and discussed. The benchmarks show a good speedup which gets improved as the problem size is increased. With the capability of the presented solver, the non-orthogonal PEEC formulation is a viable tool for modelling geometrically complex problems.

  • 162. Daroui, Danesh
    et al.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Didier, Cottet
    ABB Switzerland, Corporate Research, Schweiz.
    Dierk, Bormann
    ABB Corporate Research, Sverige.
    Engdahl, Göran
    KTH, Sverige.
    Projekt: Kretsbaserad lösare för elektromagnetisk analys av kraftelektroniksystem- Applikation mot IGBTmoduler2007Övrigt (Övrig (populärvetenskap, debatt, mm))
    Abstract [sv]

    Projektet syftar till att accelerera och adaptera den programvara, MultiPEEC,som ingick i ELEKTRA-projekt 36021 för att möjliggöra studier avelektromagnetiska effekter i avancerade kraftelektroniksystem.Programvaran bygger på en långsiktig forskningssatsning på Luleå tekniskauniversitet med syfte att kombinera lösningen av elektriska kretsar ochelektromagnetiska effekter i samma miljö med hjälp av en ekvivalent-kretsmetod(PEEC).I första delen av projektet verifierades, optimerades och stabiliseradesprogramvaran i ett mycket nära samarbete med ABB CRC. I den föreslagnaandra delen av projektet kommer programvaran att massivt accelereras föratt möjliggöra detaljstudier av elektromagnetiska effekter i bus bars ochIGBT moduler. För bus bars är det främst studier av parasitiska induktanseroch magnetiska fältmönster som är av intresse för att minimeraoscillationer, spänningstoppar och sk termiska hot spots. För IGBTmodulerna är det främst den dynamiska strömfördelningen i modulerna ochöver seriekopplade konfigurationer som studeras för att förbättrakommande produkter. Exakt med vilken metod den egen-utveckladeprogramvara kommer att accelereras utifrån bestäms under hösten 2010med en litteraturstudie som bas. Tänkbara metoder är QR decomposition,Fast multipole methods, wavelets, eller hierarkiska matrismetoder. Detprimära syftet är att accelerera lösningen av system beskrivna i frekvensdomänen under kvasi-statiska antaganden formulerade med hälp av enmodifierad nodanalys (MNA) då det passar för ovan nämnda designstudier.Vidare är det av stor vikt att kunna uppskatta felet som dessaaccelerationsmetoder introducerar i lösningen så verktyget inte blir praktisktoanvändbart.

  • 163. Daroui, Danesh
    et al.
    Stevanovic, Ivica
    ABB.
    Cottet, Didier
    ABB.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Bus bar simulations using the PEEC method2010Ingår i: 26th International Review of Progress in Applied Computational Electromagnetics ACES 2010: Tampere, Finland, April 25-29, 2010, 2010, s. 1-6Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Partial Element Equivalent Circuit (PEEC) is an integral equation based full-wave approach for the solution of combined circuit and electromagnetic problems in the time and the frequency domain. The method is fast and efficient and can be applied to different classes of problems in power electronics system design, antennas modeling, and printed circuit board simulation. This paper presents PEEC usage in simulating a system of parallel bus bars used in distributing the DC-link power in a medium voltage frequency converter. Using PEEC simulations with non-uniform meshing, the impedance of a complete bus bar structure has been simulated. The results of PEEC simulations compare very well with measured values.

  • 164.
    De Lauretis, Maria
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Multiconductor transmission lines wideband modeling: A delay-rational Green’s-function-based method2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The performance of variable-frequency drives (VFDs) commonly used in energy production plants can be severely affected by electromagnetic (EM) noise in the form of conducted disturbances.

    A VFD is composed of an inverter, a motor, and a connecting power cable. The insulated-gate bipolar transistor (IGBT) technology and the pulse-width modulation (PWM) technique, used in the inverter, amplified the role of the power cable, which experiences the so-called “high-frequency” or “transmission line” effects, such as reflections, crosstalk, and distortion. Therefore, a complete EM assessment of a VFD requires an accurate and computationally efficient mathematical model of the cable, which can be studied as a multiconductor transmission line (MTL). Accordingly, we developed the “delay-rational Green’s-function-based” (DeRaG) model that should overcome the main limitations of the existing methods in the literature. In the DeRaG model, the impedance (or admittance) matrix is the sum of a rational series and a so-called hyperbolic part realized by hyperbolic functions. The rational series consists of poles and residues and can be truncated to a suitable size by a delay extraction technique. The hyperbolic part retains the primary information of the high-frequency behaviors, such as attenuation and propagation delays, of a line; thus, the DeRaG model is a wideband model. The DeRaG model is independent of the terminations and sources of the line and enables a delayed state-space representation; it can also account for EM interference. Nevertheless, an EM assessment of a complex system can be performed only using a calculator and proper software. Most of the advanced models for MTLs have been adapted for SPICE-like transient solvers. However, power electronics applications are commonly simulated by using software packages such as Simulink that are optimized for system-level simulations. We thus proposed the implementation of the DeRaG model both in SPICE and in Simulink to embrace a larger group of users and applications. The Simulink implementation was notably proven to be extremely simple and easy to describe. In addition, we focused on the hyperbolic part to qualitatively assess the behavior of an MTL. Our investigation resulted in an outstanding outcome; namely, we provided the distortionless condition for MTLs, whereas the distortionless condition was previously defined only for single-conductor transmission lines as the well-known Heaviside condition. In conclusion, the DeRaG model is a wideband model for the EM analysis of generic transmission lines that is suitable for system-level simulations required in power electronics applications and offers new insights into the physics of the system.

     

  • 165.
    De Lauretis, Maria
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Transmission line theory for cable modeling: a delay-rational model based on Green's functions2016Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    At present, induction motors are controlled via the so-called variable-frequency drives (VFD) that allow to control the speed for the motors. The purpose of this PhD thesis is to improve electromagnetic modeling techniques for the study of conducted electromagnetic emissions in variable-frequency drives, with the aim of enhancing their reliability in energy production plants. Pulse-width-modulated voltage converters are used to feed an AC motor, and they are considered to be the primary reason for high-frequency effects in both the motor and the supply grid. In particular, high-frequency currents, known as common mode currents, flow between all energized components and the ground and travel via low-resistance and low-inductance interconnects such as the power cable between the inverter and the motor.Electrically long power cables are commonly used in VFD installations, and require particular attention. Accurate models can be obtained using the theory of multiconductor transmission lines. In the case of nonlinear terminations, such as an inverter, only time-domain analysis is possible. In recent years, several techniques have been proposed. Some of these techniques include the lumped-element equivalent circuit method, the method of characteristics (MoC) and its generalizations, and the Pad´e approach. In this context, a modeling technique based on Green’s functions has been proposed. The input/output impedance matrix is expressed as a rational series, whose poles and their residues are identified by solving algebraic equations. The primary disadvantage of this method lies in the large number of poles that is typically necessary to model the dynamics of the system, especially when electrically long interconnectsare considered. To overcome this limitation, we have proposed the Delay-Rational Green’s-Function-based Method, abbreviated as DeRaG. In this method, the line delay is extracted and, by virtue of suitable mathematical manipulation of the rational series, is incorporated through hyperbolic functions. The delay extraction enables the use of a reduced number of poles and improves the accuracy of the model in general, avoiding any ringing effects in the time-domain response. The primary advantage of the proposed method compared with other well-known techniques lies in the delayed state-space representation. The obtained model can be computed regardless of the terminations and/or sources, and the terminal conditions can be immediately and essentially incorporated.The next step will be to simulate the entire inverter-cable-motor system. The partial element equivalent circuit (PEEC) technique will be used to model the interconnects as well as the discontinuities in the power cable that can be caused, for example, by switch disconnectors. The theoretical results will be verified against experimental measurements. The final objective is to provide new techniques for modeling the electrodynamics of variable-frequency drives to allow their complete EMC assessment as early as the design stage and to enable the planning of corrective actions in advance.

  • 166.
    De Lauretis, Maria
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Antonini, Giulio
    Department of Electrical Engineering, University of L’Aquila.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    A Delay-Rational Model of Lossy Multiconductor Transmission Lines with Frequency Independent Per-Unit-Length Parameters2015Ingår i: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187X, Vol. 57, nr 5, s. 1235-1245Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cables, printed circuit boards, and VLSI interconnects are commonly modelled as multiconductor transmission lines. Models of electrically long transmission lines are memory and time consuming. In this paper, a robust and efficient algorithmfor the generation of a delay-based model is presented. The impedance representation via the open-end matrix Z is analyzed. In particular, the rational formulation of Z in terms of poles and residues is exploited for both lossless and lossy cases. The delaysof the lines are identified, and explicitly incorporated into the model. A model order reduction of the system is automatically performed, since only a limited number of poles and residues are included in the rational part of the model, whereas the highfrequency behaviour is captured by means of closed expressions that accounts for the delays. The proposed method is applied to two relevant examples and validated through the comparison with reference methods. The time domain solver is found to be more accurate and significantly faster than the one obtained froma pure-rational model.

  • 167.
    De Lauretis, Maria
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Antonini, Giulio
    University of L'Aquila .
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    A Simulink implementation of the Delay-Rational Green's-Function-based Method for Multiconductor Transmission Lines2018Ingår i: EMC Europe 2018, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2018, s. 817-822, artikel-id 8485071Konferensbidrag (Refereegranskat)
    Abstract [en]

    The electromagnetic compatibility (EMC) performances of a product can seriously be affected by interconnects. Interconnects can be studied by using the multiconductor transmission lines (MTLs) theory. Mathematical models of MTLs are normally validated with the aid of well-known software, such as MATLAB or PSpice. Simulink is part of the MATLAB suite but is not frequently used, and it is often underestimated both in academia and in the university education. In this paper, we briefly review the mathematical model for MTLs called DeRaG, which is a rational model based on delay extraction. Then, we propose the corresponding Simulink implementation for a 3-conductor transmission line. The Simulink has high readability, is accurate and the simulation time is remarkably faster than the corresponding model obtained in PSpice.

  • 168.
    De Lauretis, Maria
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Antonini, Giulio
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB. Università Degli Studi di l'Aquila.
    A SPICE Realization of the Delay-Rational Green's-Function-based Method for Multiconductor Transmission Lines2016Ingår i: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187X, Vol. 58, nr 4, s. 1158-1168Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Virtual prototyping has become an unavoidable step in the design of electrical and electronic systems.In this context, time-domain models have to be efficiently embedded in circuit simulator environments, such as SPICE-like transient simulators.Recently, the authors focused on the interconnections, modeled using the multiconductor transmission lines theory, and a Delay-Rational method has been developed, based on Green's functions and line-delay extraction.This work presents a SPICE synthesis of the Delay-Rational method previously developed by the authors.The solution was tested for three transmission lines with frequency-independent per-unit-length parameters.We compared the SPICE results of the Delay-Rational method with those of two standard techniques: one based on a pure rational model and one based on the inverse fast Fourier transform.The time-domain simulations in SPICE of the Delay-Rational method show both accuracy and a remarkable reduction in the number of components used with respect to a purely rational approach, by virtue of the delay extraction.

  • 169.
    De Lauretis, Maria
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB. Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Antonini, Giulio
    Università Degli Studi dell'Aquila.
    Delayed Impedance Models of Two-Conductor Transmission Lines2014Ingår i: 2014 International Symposium on Electromagnetic Compatibility - EMC Europe 2014: Swedish Exhibition and Congress Centre, Gothenburg, Sweden : 1 - 4 September, Piscataway, NJ: IEEE Communications Society, 2014, s. 670-675, artikel-id 6930989Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a new delayed model of two-conductortransmission lines with frequency-independent per-unit-length parameters. In particular, the line delay extractionproblem is considered. By use of a dyadic Green’s functionmacromodel method, the rational form of the open-endimpedance matrix allows an easy identification of poles andresidues, and a new technique for the extraction of the linedelay in an analytical way is gained, without any impact onthe complexity of the line macromodel itself. By use of Laplaceand Fourier transforms, the transfer function is expressed interms of the Dirac comb. The delay is then easily identified anddirectly incorporated into the system impulse response. Giving acurrent-controlled representation, the port voltages are evaluated.Thanks to the formulation of the transfer function by use ofthe Dirac comb, the convolution product is avoided, gainingaccuracy and time-saving from a computational point of view.Numerical results confirm the validity of the proposed delay-extractiontechnique. The basic ideas for the extension of theproposed technique to the lossy case are outlined.

  • 170.
    De Lauretis, Maria
    et al.
    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 .
    Delayed-rational Green's-function-based method of transmission lines and the Heaviside condition2016Ingår i: 2016 IEEE Electrical Design of Advanced Packaging and Systems Symposium, EDAPS 2016, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 143--145, artikel-id 7893147Konferensbidrag (Refereegranskat)
    Abstract [en]

    In electronics as well as in communications, it ishighly desirable to be able to transmit a signal that is preservedfrom any distortions that is due to the lossy nature of themedium in which the signal travels, normally a transmission line.In this paper, we exploit the connections between the delayedGreen’s-function-based method from the authors and the wellknowndistortionless Heaviside condition. It is found that, inthe method, an important results was already present but itsimportance not yet understood. In particular, we prove that weare able to identify the distortionless transmission line associatedto a generic transmission line. We consider only 1-conductortransmission lines, with frequency-independent per-unit-lengthparameters. The multiconductor transmission-line case will beaddressed in future works.

  • 171.
    De Lauretis, Maria
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Antonini, Giulio
    Department of Electrical Engineering, University of L’Aquila.
    Delay-Rational Model of Lossy and Dispersive Multiconductor Transmission Lines2015Ingår i: IEEE International Symposium on Electromagnetic Compatibility (EMC), 2015 [joint conference with] EMC Europe: Dresden, 16-22 Aug. 2015, Piscataway,NJ: IEEE Communications Society, 2015, s. 969-974, artikel-id 7256297Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, the transient analysis of lossy anddispersive multiconductor transmission lines is considered. Theexisting Green’s function-based method is extended to explicitlyinclude delays extraction, thus leading to a significant compressedtime-domain state-space model. The proposed method is mainlybased on poles and residues asymptotic analysis and losslessdelays extraction. The resulting hybrid state-space model incorporatesDirac-combs in the input and results into a reducednumber of state variables. A test case has been considered inorder to clearly demonstrate the effectiveness of the proposedmethodology. The results are compared with the original rationalGreen’s function method, and with the standard inverse fastFourier transform technique.

  • 172.
    De Lauretis, Maria
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Antonini, Giulio
    Department of Electrical Engineering, University of L’Aquila.
    Romano, Daniele
    University of L’Aquila.
    Enhanced Delay-Rational Green's Method for Cable Time Domain Analysis2015Ingår i: 2015 International Conference on Electromagnetics in Advanced Applications (ICEAA): Turin, 7-11 Sept. 2015, Piscataway, NJ: IEEE Communications Society, 2015, s. 1228-1231Konferensbidrag (Refereegranskat)
    Abstract [en]

    State-space models of multiconductor transmissionlines can be generated by means of the Green’s function basedmethod which allows to write the open-end impedance in arational form as an infinite sum of “modal impedances”. Itcan be then embedded in a circuit simulation environment forefficient time domain analysis. The previous rational approachhas been improved through a proper mathematical formulation,that makes use of explicit delay extraction and pole/residueasymptotic behavior. Nevertheless, the computation of the polesbecomes computationally expensive when the number of conductorsincreases, since the zeros of high order polynomials haveto be evaluated. A rational fitting over the “modal impedances”is proposed, which allows a fast identification of the poles that,together with the delays, model the high frequency behavior ofthe cable in terms of standard hyperbolic functions. The lowfrequencybehavior is captured by a reduced size state-spacemodel, via rational fitting. Numerical results confirm the accuracyof the proposed modeling approach for electrically long cables,with a large number of conductors.

  • 173.
    del Campo, Sergio Martin
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Albertsson, Kim
    Luleå tekniska universitet, Verksamhetsstöd, IT-Service.
    Nilsson, Joakim
    Engineering Physics student at the Luleå University of Technology.
    Eliasson, Jens
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Sandin, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    FPGA prototype of machine learning analog-to-feature converter for event-based succinct representation of signals2013Ingår i: IEEE International Workshop on Machine Learning for Signal Processing, Piscataway, NJ: IEEE Signal Processing Society, 2013, artikel-id 6661996Konferensbidrag (Refereegranskat)
    Abstract [en]

    Sparse signal models with learned dictionaries of morphological features provide efficient codes in a variety of applications. Such models can be useful to reduce sensor data rates and simplify the communication, processing and analysis of information, provided that the algorithm can be realized in an efficient way and that the signal allows for sparse coding. In this paper we outline an FPGA prototype of a general purpose "analog-to-feature converter", which learns an overcomplete dictionary of features from the input signal using matching pursuit and a form of Hebbian learning. The resulting code is sparse, event-based and suitable for analysis with parallel and neuromorphic processors. We present results of two case studies. The first case is a blind source separation problem where features are learned from an artificial signal with known features. We demonstrate that the learned features are qualitatively consistent with the true features. In the second case, features are learned from ball-bearing vibration data. We find that vibration signals from bearings with faults have characteristic features and codes, and that the event-based code enable a reduction of the data rate by at least one order of magnitude.

  • 174.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    A novel massflow meter based on ultrasound technology1993Ingår i: Proceedings of International Symposium on Heat Metering - District Heating, Norges tekniske högskola , 1993Konferensbidrag (Refereegranskat)
  • 175.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    A review of development trends in ultrasonic flowmeters2000Ingår i: Proceedings: Global Conference on Flow Metering & Control for New Millennium, 2000Konferensbidrag (Refereegranskat)
  • 176.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Activity: Artemis ITEA co summit: application to process control2008Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 177.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Activity: EU-NSF workshop 20082008Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 178.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Activity: Euroheat & Power R&D Workshop: High Efficiency - Improved Building Installations and Customer Comfort2006Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 179.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Activity: IDEA Annual Conference & Trade Show, Setting the Pace, Leading the Way2007Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 180.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Activity: International Conference on Advanced Mathematical and Computational Tools in Metrology, AMCTM 20052005Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 181.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Activity: MEDTEC Exhibition and Conference2006Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 182.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Aktivitet: Reactive networked sensor systems and their application2006Övrigt (Övrig (populärvetenskap, debatt, mm))
  • 183.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Aktivitet: Reactive networked sensor systems and their applicaton2006Övrigt (Övrig (populärvetenskap, debatt, mm))
  • 184.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Aktivitet: Reglermöte 20082008Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 185.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Aktivitet: Sveriges Energiting 20072007Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 186.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Arrowhead Framework: A Local Cloud Approach to Automation2015Konferensbidrag (Övrigt vetenskapligt)
  • 187.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Automation Systems from IoT - Arrowhead Framework: concepts and basic architecture2015Konferensbidrag (Övrigt vetenskapligt)
  • 188.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Building Automation Systems from Internet of Things2015Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Nowadays products and services are produced and delivered by numerous stakeholders, all required to interact with suppliers and customers in an efficient and flexible way. Energy consumption and energy usage environmental impact have become of paramount concern in those activities. Automation technology offers solutions to deal with those challenges. Automation technology as we know it today, however, has got some limitations. The emerging era of the Internet of Things (IoT) with its ease to build complex system of systems (SoS) opens new perspectives in the automation area.In this context, the European project Arrowhead envisions “Collaborative automation by networked embedded devices”. This necessitates a wide interoperability of devices, as well as systems and platforms. The proposed framework provides such interoperability at the service level. The Arrowhead framework efficiently support the development, deployment and operation of interconnected, collaborative systems. Arrowhead cloud automation systems are based on automation devices such as sensors, actuators, controllers, and others transformed into IoT-type of devices and systems adopting the Service Oriented Architecture philosophy. The building elements of a cloud automation system are systems that provide and consume services, and cooperate as systems of systems from which automation services like monitoring, control, optmisation, analysitcs etc are created. The building of complete automation systems is supported by orchestration and authorisation services.The presentation is going to discuss the new automation challenges, and solutions the Arrowhead framework offers.

  • 189.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Communicating sensors for better diagnosises2007Ingår i: Medicinteknikdagarna 2007, Svensk förening för medicinsk teknik , 2007, s. 62-Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Current health care have developed a large number of sensors and measurements methodologies. Each of them in most cases dedicated for a single measurement to be made by an medical doctor or a nurse. It seams apparent that more and preciser information can be obtained if these measurements can be made under normal living conditions i.e. not at the hospital. This puts a focus to questions like mobility, ease of application, calibration and data communication. Thus issues like sensor size, weight, means of communication, field calibration, power lifetime etc. becomes extremely important. There is a long development in mobile medical monitoring/aiding technology like pace makers. Here size and power life time is feasible for patients. Communication means to the pace makers is also improved but most often requires a visit to the hospital. For much medical monitoring like blood pressure, ECG, pulse, etc. it would be beneficial to enable continuous monitoring with local on board diagnosis. The current strong research in light weight sensor nodes and sensor networks will open new perspectives to this. As an example of this I will discuss an mobile ECG development made jointly by Fraunhofer institute in Erlangen and Luleå University of Technology, EISLAB. The total device weighs less than 50g including battery. It supports Internet communication using Bluetooth connecting to the Internet via a standard mobile phone as access point. The device has on-board limited computation memory resources enabling simple local data analysis. This will reduce communication needs to "awake" messages and "alarm" messages upon which continuous data can be transfered to a medical center. This local analysis strategy will enable power life times for a 50 g sensor of many months according to first evaluations.

  • 190.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Communication Technology in Mobile and Pervasive Computing2012Ingår i: Mobile and pervasive computing in construction, Ames, Iowa: John Wiley & Sons, 2012, s. 26-36Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Mobile and pervasive computing is dependent to a large extent on the enabling communications infrastructure. This chapter provides a brief introduction to some of the key elements of this infrastructure-devices, communication standards and protocols, and proprietary systems. Each of these is described in turn and their applicability to mobile and pervasive computing briefly discussed. Many of the other chapters in this book take advantage of several of the technologies and protocols discussed here.

  • 191.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Device and system diagnosis based on embedded sensing and intelligence2006Ingår i: Condition Monitoring and Diagnostic Engineering Management, COMADEM 2006: proceedings of the 19th International Congress, 12-15 June 2006, Luleå, Sweden / [ed] Uday Kumar; Aditya Parida; Raj B.K.N. Rao, Luleå: Luleå tekniska universitet, 2006Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Maintenance of industrial infrastructure, machinery and communication is becoming a more and more critical issue in our society. The technology development in sensors and sensor networks will enable the embedding of "intelligence" into infrastructure, machinery and communication. Here Internet will become the communication paradigm to build on and already available communication infrastructure like the mobile phone networks will become the access network infrastructure. I will discuss such technology development including its capability for autonomous integration into its environment and autonomous operation. Thus enabling device and system diagnosis made available.

  • 192.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Device for temperature compensation in an acoustic flow meterPatent (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    A meter includes a casing (1) with a fluid passage (2), in which two transducer mountings (3, 4) arranged at a distance (Lb) from each other support two transducers (5, 6) which are acoustically opposed to each other. Between the transducers (5, 6) there is a distance (Lu) over which they transmit and receive sound pulses through a fluid which in a direction (a) flows through the fluid passage (2). On the basis of the transit times of the sound pulses over the distance (Lu) both countercurrently with and countercurrently to the direction of flow (a), e.g. the velocity of the flow of the fluid is then calculated. A compensating device (8, 9) is arranged between at least one of the transducers (5, 6) and one of the transducer mounts (3, 4). The compensating device (8, 9) is made of a material having a known function of thermal expansion and having such a length that a longitudinal change, caused by a change in temperature of the fluid, of the distance (Lb) between the transducer mounts (3, 4) and, thus, of the distance (Lu) between the transducers (5, 6) is essentially compensated for by an opposite longitudinal change of the compensating device (8, 9).

  • 193.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Dynamic installation effects on ultrasonic flow meters1996Ingår i: Proceedings of the 8th International Conference on Flow Measurement: FLOMEKO '96 / [ed] Zhang Baoyu, Beijing: Standard Press of China , 1996, s. 192-Konferensbidrag (Refereegranskat)
  • 194.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Flow measurement facilities2006Ingår i: Flow Measurement and Instrumentation, ISSN 0955-5986, E-ISSN 1873-6998, Vol. 17, nr 3, s. 139-Artikel i tidskrift (Övrigt vetenskapligt)
  • 195.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Fluid composition monitor using electrode pairPatent (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    The measurement body comprises two concentric metal tubes, one inner and one outer (3), sepd. by a distance component of electrically insulating material. The two tubes are connected by leads to a vector impedance meter for measuring phase angle. The body is fitted in a section of a tube in which the fluid to be monitored is transported, or, alternatively, inside a tube or tank in which the fluid is stored. The fluid fills the space inside the inner tube and that between it and the outer tube. The ends of the inner tube may be blocked so that only the space between the two tubes is filled with fluid. Thus, a capacitor is formed by the measurement body, and the two tubes constitute its electrodes. When monitoring the compsn. of a fluid, a known high frequency alternating voltage is fed over the two electrodes, and the phase angle between the voltage and the resultant current is measured, it being preferable for the frequency of the voltage or current ot be in the interval of 250 kHz.

  • 196.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    IoT Automation: Arrowhead Framework2017Samlingsverk (redaktörskap) (Refereegranskat)
    Abstract [en]

    This book presents an in-depth description of the Arrowhead Framework and how it fosters interoperability between IoT devices at service level, specifically addressing application. The Arrowhead Framework utilizes SOA technology and the concepts of local clouds to provide required automation capabilities such as: real time control, security, scalability, and engineering simplicity. Arrowhead Framework supports the realization of collaborative automation; it is the only IoT Framework that addresses global interoperability across multiplet SOA technologies. With these features, the Arrowhead Framework enables the design, engineering, and operation of large automation systems for a wide range of applications utilizing IoT and CPS technologies. The book provides application examples from a wide number of industrial fields e.g. airline maintenance, mining maintenance, smart production, electro-mobility, automative test, smart cities—all in response to EU societal challenges.

  • 197.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    IoT Automation: Arrowhead Framework2017Bok (Övrigt vetenskapligt)
  • 198.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    IoT automation value creation enabled by the Arrowhead Framework2015Konferensbidrag (Övrigt vetenskapligt)
  • 199.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Kartläggning av utvecklingsläget för ultraljudsflödesmätare1998Rapport (Övrigt vetenskapligt)
  • 200.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Local Cloud Internet of Things Automation: Technology and Business Model Features of Distributed Internet of Things Automation Solutions2017Ingår i: IEEE Industrial Electronics Magazine, ISSN 1932-4529, E-ISSN 1941-0115, Vol. 11, nr 4, s. 8-21Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The hype concerning digitalization is increasing the demand for new generations of automation systems. Concepts like Reference Architecture Model Industry 4.0 (RAMI 4.0) give us models but do not tell us how to facilitate actual implementations. This article discusses the transition from legacy automation technology as defined by ISA-95 to highly distributed Internet of Things (IoT)- and system of systems (SoS)- based automation systems that fully utilize Internet technologies, thus enabling the implementation of Industry 4.0 and RAMI 4.0 models. Distributed IoT automation systems have a number of general requirements concerning real-time performance, security, engineering cost, scalability, and interoperability. Meeting these requirements is necessary to enable possibilities for a realworld implementation of IoT automation. A key concept is local automation clouds. The discussion is based on a particular example of such an automation integration platform, the Arrowhead Framework.

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