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Flatness-Based Feed-Forward control Design for Solenoid Actuators Considering Eddy Currents

IFAC-PapersOnLine 2019年第15期52卷 567-572页

作者： Tristan Braun Johannes Reuter Joachim Rudolph ZF Friedrichshafen AG Corporate Research & Development 88038 Friedrichshafen Germany Institute of System Dynamics Konstanz University of Applied Sciences 78462 Konstanz Germany Chair of Systems Theory and Control Engineering Saarland University Campus A5 1 66123 Saarbrücken Germany

Flatness-based feed-forward control of solenoid actuators is considered. For precise motion planning and accurate steering of conventional solenoids, eddy currents cannot be neglected. The system of ordinary differential equations including eddy currents, that describes the nonlinear dynamics of such actuators, is not differentially flat. Thus, a distributed parameter approach based on a diffusion equation is considered, that enables the parametrization of the eddy current by the armature position and its time derivatives. In order to design the feedforward control, the distributed parameter model of the eddy current subsystem is combined with a typical nonlinear lumped parameter model for the electrical and mechanical subsystems of the solenoid. The control design and its application are illustrated by numerical and practical results for an industrial solenoid actuator.

关键词： differential flatness feed-forward control motion planning distributed parameter systems diffusion equation eddy currents solenoid valves

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High performance solution of skew-symmetric eigenvalue problems with applications in solving the Bethe-Salpeter Eigenvalue Problem

arXiv

引用

arXiv 2019年

作者： Penke, Carolin Marek, Andreas Vorwerk, Christian Draxl, Claudia Benner, Peter Computational Methods in Systems and Control Theory Max Planck Institute for Dynamics of Complex Technical Systems Germany Max Planck Computing and Data Facility Garching Germany Institut für Physik and IRIS Adlershof Humboldt-Universität zu Berlin Berlin Germany

We present a high-performance solver for dense skew-symmetric matrix eigenvalue problems. Our work is motivated by applications in computational quantum physics, where one solution approach to solve the so-called Bethe-Salpeter equation involves the solution of a large, dense, skew-symmetric eigenvalue problem. The computed eigenpairs can be used to compute the optical absorption spectrum of molecules and crystalline systems. One state-of-the art high-performance solver package for symmetric matrices is the ELPA (Eigenvalue SoLvers for Petascale Applications) library. We exploit a link between tridiagonal skew-symmetric and symmetric matrices in order to extend the methods available in ELPA to skew-symmetric matrices. This way, the presented solution method can benefit from the optimizations available in ELPA that make it a well-established, efficient and scalable library. The solution strategy is to reduce a matrix to tridiagonal form, solve the tridiagonal eigenvalue problem and perform a back-transformation for eigenvectors of interest. ELPA employs a one-step or a two-step approach for the tridiagonalization of symmetric matrices. We adapt these to suit the skew-symmetric case. The two-step approach is generally faster as memory locality is exploited better. If all eigenvectors are required, the performance improvement is compensated by the additional back transformation step. We exploit the symmetry in the spectrum of skew-symmetric matrices, such that only half of the eigenpairs need to be computed, making the two-step approach the favorable method. We compare performance and scalability of our method to the only available high-performance approach for skew-symmetric matrices, an indirect route involving complex arithmetic. In total, we achieve a performance that is up to 3.67 higher than the reference method using Intel’s ScaLAPACK implementation. Our method is freely available in the current release of the ELPA *** Codes 65Y05, 15B57 Copyright © 2019

关键词： Eigenvalues and eigenfunctions

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Sustainable research software hand-over

arXiv

引用

arXiv 2019年

作者： Fehr, Jörg Himpe, Christian Rave, Stephan Saak, Jens Institute of Engineering and Computational Mechanics University of Stuttgart Pfaffenwaldring 9 Stuttgart70569 Germany Computational Methods in Systems and Control Theory Max Planck Institute for Dynamics of Complex Technical Systems Sandtorstr. 1 Magdeburg39106 Germany Institute for Computational and Applied Mathematics University of Münster Einsteinstrasse 62 Münster48149 Germany

Scientific software projects evolve rapidly in their initial development phase, yet at the end of a funding period, the completion of a research project, thesis, or publication, further engagement in the project may slow down or cease completely. To retain the invested effort for the sciences, this software needs to be preserved or handed over to a succeeding developer or team, such as the next generation of (PhD) students. Comparable guides provide top-down recommendations for project leads. This paper intends to be a bottom-up approach for sustainable hand-over processes from a developer's perspective. An important characteristic in this regard is the project's size, by which this guideline is structured. Furthermore, checklists are provided, which can serve as a practical guide for implementing the proposed *** Codes 68N30, 97N80, 97P99 Copyright © 2019, The Authors. All rights reserved.

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Residual minimizing shift parameters for the low-rank ADI iteration

arXiv

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arXiv 2018年

作者： Kürschner, Patrick Max Planck Institute for Dynamics of Complex Technical Systems Computational Methods in Systems and Control Theory Magdeburg Germany

The low-rank alternating directions implicit (LR-ADI) iteration is a frequently employed method for efficiently computing low-rank approximate solutions of large-scale Lyapunov equations. In order to achieve a rapid error reduction, the iteration requires shift parameters whose selection and generation is often a difficult task, especially for nonsymmetric coefficients in the Lyapunov equation. This article represents a follow up of Benner et al. [ETNA, 43 (2014–2015), pp. 142–162] and investigates self-generating shift parameters based on a minimization principle for the Lyapunov residual norm. Since the involved objective functions are too expensive to evaluate and, hence, intractable, compressed objective functions are introduced which are efficiently constructed from the available data generated by the LR-ADI iteration. Several numerical experiments indicate that these residual minimizing shifts using approximated objective functions outperform existing precomputed and dynamic shift parameter selection techniques, although their generation is more involved.15A06, 65F10, 65F30 Copyright © 2018, The Authors. All rights reserved.

关键词： Lyapunov functions

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Improving the performance of numerical algorithms for the bethe-salpeter eigenvalue problem

Improving the performance of numerical algorithms for the be...

引用

89th Annual Meeting on the International Association of Applied Mathematics and Mechanics, GAMM 2018

作者： Benner, Peter Marek, Andreas Penke, Carolin Max Planck Institute for Dynamics of Complex Technical Systems: Computational Methods in Systems and Control Theory Sandtorstr. 1 Magdeburg39106 Germany Max Planck Computing and Data Facility Gießenbachstraße 2 Garching85748 Germany

The Bethe-Salpeter eigenvalue problem arises in the computation of the electronic structure of many-body physical systems. The resulting matrix is complex, admits a certain block structure and can become extremely large. This raises the need for structure-preserving algorithms running in parallel on high performance compute clusters. In this paper we examine how a recently proposed direct method given in the BSEPACK library can be improved using eigenvalue solvers from the ELPA library. For large matrices a runtime reduction of up to 80% is achieved. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

关键词： Electronic structure

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Local Refinement of l-complete Approximations for Supervisory control of Hybrid systems

引用

IFAC-PapersOnLine 2018年第7期51卷 472-479页

作者： Yang, Jung–Min Moor, Thomas Raisch, Jörg School of Electronics Engineering Kyungpook National University 80 Daehakro Bukgu Daegu41566 Korea Republic of Lehrstuhl für Regelungstechnik at Friedrich-Alexander Universität Erlangen-Nürnberg ErlangenD-91058 Germany Fachgebiet Regelungssysteme Technische Universitaet Berlin Berlin10587 Germany Systems and Control Theory Group Max Planck Institute for Dynamics of Complex Technical Systems MagdeburgD-39106 Germany

l-complete approximation is a discrete abstraction method for a specific class of hybrid control problems involving purely discrete specifications. It allows for global refinement if the subsequent synthesis of supervisory control should fail for the currently selected abstraction level. In this paper, we present a methodology of local refinement for l-complete approximations. If the strongest l-complete approximation of a given hybrid system does not guarantee the existence of a suitable supervisor for a given specification, the proposed scheme refines the abstract model only in a local set of states that violate a controllability condition. Compared to the standard unfocused and global refinement procedure, this may significantly reduce the computational burden both in the abstraction step and the subsequent controller synthesis step. © 2018

关键词： Hybrid systems Abstracting controllability Discrete event simulation Discrete time control systems Specifications Abstract modeling Computational burden controllability condition controller synthesis Discrete abstraction l complete approximations Local refinement Supervisory control

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Identification of the energy system critical elements using the PARMONC library

引用

Journal of Physics: Conference Series 2021年第1期1715卷

作者： A V Edelev M A Marchenko O Yu Basharina Melentiev Energy Systems Institute SB RAS Lermontov St. 130 Irkutsk Russia 664033 Institute of Computational Mathematics and Mathematical Geophysics SB RAS 6 Ac. Lavrentieva ave. Novosibirsk Russia 630090 Novosibirsk State University Novosibirsk-90 2 Russia 630090 Matrosov Institute for System Dynamics and Control Theory SB RAS Lermontov St. 134 Irkutsk Russia 664033

In this paper, we presented a Monte Carlo-based approach for vulnerability analyse of energy systems. For high-performance Monte Carlo simulation the PARMONC software library was used. The PARMONC is implemented on high-performance clusters of the Siberian Supercomputer Center. The PARMONC effectively launches parallel stochastic simulation on supercomputers with different architectures. The proposed approach was applied was applied for the identification and ranking the most important elements of a real-world natural gas supply system.

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Linear low-rank parameter-dependent fluid-structure interaction discretization in 2d

Linear low-rank parameter-dependent fluid-structure interact...

引用

89th Annual Meeting on the International Association of Applied Mathematics and Mechanics, GAMM 2018

作者： Weinhandl, Roman Benner, Peter Richter, Thomas Max Planck Institute for Dynamics of Complex Technical Systems: Computational Methods in Systems and Control Theory Sandtorstr. 1 Magdeburg39106 Germany Otto von Guericke University Magdeburg Faculty of Mathematics Universitätsplatz 2 Magdeburg39106 Germany

Fluid-structure interaction problems involve material parameters such as the shear modulus of the solid and the dynamic fluid viscosity. In order to examine the behaviors of various solids and adapt the problems to different fluid configurations there is a need to vary such material parameters flexibly. This can be done by a parameter-dependent fluid-structure interaction discretization which yields a system matrix that has block diagonal structure. As also discussed in [2], the resulting equation is equivalent to a matrix equation which allows for a low-rank approach where the iterate is represented by a tensor. A low-rank GMRES variant similar to what was discussed in [1] can then be applied to such parameter-dependent systems. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

关键词： Fluid structure interaction

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Universal Spectra of Random Lindblad Operators

引用

Physical Review Letters 2019年第14期123卷 140403-140403页

作者： Sergey Denisov Tetyana Laptyeva Wojciech Tarnowski Dariusz Chruściński Karol Życzkowski Department of Computer Science OsloMet–Oslo Metropolitan University NO-0130 Oslo Norway Department of Control Theory and Systems Dynamics Lobachevsky University Gagarina Avenue 23 Nizhny Novgorod 603950 Russia Marian Smoluchowski Institute of Physics Uniwersytet Jagielloński Krakow Poland Institute of Physics Faculty of Physics Astronomy and Informatics Nicolaus Copernicus University Grudziadzka 5/7 87–100 Torun Poland Center for Theoretical Physics Polish Academy of Sciences 02-668 Warszawa Poland

To understand the typical dynamics of an open quantum system in continuous time, we introduce an ensemble of random Lindblad operators, which generate completely positive Markovian evolution in the space of the density matrices. The spectral properties of these operators, including the shape of the eigenvalue distribution in the complex plane, are evaluated by using methods of free probabilities and explained with non-Hermitian random matrix models. We also demonstrate the universality of the spectral features. The notion of an ensemble of random generators of Markovian quantum evolution constitutes a step towards categorization of dissipative quantum chaos.

关键词： Open quantum systems Quantum chaos Quantum master equation Random matrix theory

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Generation of Code for Reading Data from the Declarative File Format Specifications Written in Language FlexT

Generation of Code for Reading Data from the Declarative Fil...

引用

Ivannikov ISPRAS Open Conference (ISPRAS)

作者： Alexei Hmelnov Hmelnov Andrei Mikhailov Laboratory of Complex information systems Matrosov Institute for System Dynamics and Control Theory of Siberian Branch of Russian Academy of Sciences Irkutsk Russia

ISBN: (纸本)9781728112763;9781728112756

The language FlexT (Flexible Types) is intended for specification of binary data formats. The language is declarative and designed to be well understood for human readers. Its main elements are the data type declarations, which look very much like the usual type declarations of the imperative programming languages, but are more flexible. While the primary purpose of the language FlexT development was to make the binary data understandable by displaying them according to the format specifications, recently we have implemented the code generator, which can produce data reading code in some imperative languages from the specifications. By now we have implemented the code generation for the most widely used FlexT data types, but some complex types like that used in specifications of machine instructions' encoding are not supported yet. The current capabilities of the code generator are well characterized by that it have successfully produced a full-featured data reader code for the well-known for the GIS community Shape file format. In the article we first give a review of the features of the modern projects oriented to specification of binary file formats and consider their code generation capabilities. Then we briefly review the main features of the FlexT language. Finally we describe the main approaches that we use for the code generation.

关键词： Protocols Computer languages Generators Task analysis Syntactics Arrays Encoding

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