TY - CHAP A1 - Weiss, Ruven A1 - Albrecht, Ludwig A1 - Reuter, Johannes A1 - Gehan, Olivier T1 - A control-oriented thermal model for a moving dual-layer substrate T2 - 9th Vienna International Conference on Mathematical Modelling (Mathmod 2018), 21-23 February 2018, Vienna, Austria - (IFAC-PapersOnLine Vol. 51, Iss. 2) N2 - This paper describes an early lumping approach for generating a mathematical model of the heating process of a moving dual-layer substrate. The heat is supplied by convection and nonlinearly distributed over the whole considered spatial extend of the substrate. Using CFD simulations as a reference, two different modelling approaches have been investigated in order to achieve the most suitable model type. It is shown that due to the possibility of using the transition matrix for time discretization, an equivalent circuit model achieves superior results when compared to the Crank-Nicolson method. In order to maintain a constant sampling time for the in-visioned-control strategies, the effect of variable speed is transformed into a system description, where the state vector has constant length but a variable number of non-zero entries. The handling of the variable transport speed during the heating process is considered as the main contribution of this work. The result is a model, suitable for being used in future control strategies. Y1 - 2018 U6 - http://dx.doi.org/10.1016/j.ifacol.2018.03.056 SN - 2405-8963 N1 - Volltextzugriff für Angehörige der Hochschule Konstanz möglich SP - 325 EP - 330 ER - TY - JOUR A1 - Braun, Tristan A1 - Reuter, Johannes A1 - Rudolph, Joachim T1 - A singular perturbation approach to nonlinear observer design with an application to electromagnetic actuators JF - International Journal of Control N2 - A constructive method for the design of nonlinear observers is discussed. To formulate conditions for the construction of the observer gains, stability results for nonlinear singularly perturbed systems are utilised. The nonlinear observer is designed directly in the given coordinates, where the error dynamics between the plant and the observer becomes singularly perturbed by a high-gain part of the observer injection, and the information of the slow manifold is exploited to construct the observer gains of the reduced-order dynamics. This is in contrast to typical high-gain observer approaches, where the observer gains are chosen such that the nonlinearities are dominated by a linear system. It will be demonstrated that the considered approach is particularly suited for self-sensing electromechanical systems. Two variants of the proposed observer design are illustrated for a nonlinear electromagnetic actuator, where the mechanical quantities, i.e. the position and the velocity, are not measured KW - Nonlinear observers KW - Singular perturbations KW - Stability analysis KW - Electromagnetic actuators KW - Self-sensing Y1 - 2018 U6 - http://dx.doi.org/10.1080/00207179.2018.1539873 SN - 1366-5820 SN - 0020-7179 IS - Published online: 29 Oct 2018 ER - TY - CHAP A1 - Freudenberger, Jürgen A1 - Rajab, Mohammed A1 - Shavgulidze, Sergo T1 - A soft-input bit-flipping decoder for generalized concatenated codes T2 - IEEE International Symposium on Information Theory (ISIT), 17-22 June 2018, Vail, CO, USA N2 - Generalized concatenated (GC) codes with soft-input decoding were recently proposed for error correction in flash memories. This work proposes a soft-input decoder for GC codes that is based on a low-complexity bit-flipping procedure. This bit-flipping decoder uses a fixed number of test patterns and an algebraic decoder for soft-input decoding. An acceptance criterion for the final candidate codeword is proposed. Combined with error and erasure decoding of the outer Reed-Solomon codes, this bit-flipping decoder can improve the decoding performance and reduce the decoding complexity compared to the previously proposed sequential decoding. The bit-flipping decoder achieves a decoding performance similar to a maximum likelihood decoder for the inner codes. Y1 - 2018 UR - https://ieeexplore.ieee.org/document/8437537 U6 - http://dx.doi.org/10.1109/ISIT.2018.8437537 SN - 2157-8117 N1 - Volltextzugriff für Angehörige der Hochschule Konstanz via Datenbank IEEE Xplore möglich. SP - 1301 EP - 1305 ER - TY - JOUR A1 - Freudenberger, Jürgen A1 - Rajab, Mohammed A1 - Shavgulidze, Sergo T1 - A Source and Channel Coding Approach for Improving Flash Memory Endurance JF - IEEE Transactions on Very Large Scale Integration (VLSI) Systems N2 - The introduction of multiple-level cell (MLC) and triple-level cell (TLC) technologies reduced the reliability of flash memories significantly compared with single-level cell flash. With MLC and TLC flash cells, the error probability varies for the different states. Hence, asymmetric models are required to characterize the flash channel, e.g., the binary asymmetric channel (BAC). This contribution presents a combined channel and source coding approach improving the reliability of MLC and TLC flash memories. With flash memories data compression has to be performed on block level considering short-data blocks. We present a coding scheme suitable for blocks of 1 kB of data. The objective of the data compression algorithm is to reduce the amount of user data such that the redundancy of the error correction coding can be increased in order to improve the reliability of the data storage system. Moreover, data compression can be utilized to exploit the asymmetry of the channel to reduce the error probability. With redundant data, the proposed combined coding scheme results in a significant improvement of the program/erase cycling endurance and the data retention time of flash memories. Y1 - 2018 UR - https://ieeexplore.ieee.org/document/8290563 U6 - http://dx.doi.org/10.1109/TVLSI.2018.2797078 SN - 1557-9999 N1 - Volltextzugriff für Angehörige der Hochschule Konstanz via Datenbank IEEE Xplore möglich. VL - 26 IS - 5 SP - 981 EP - 990 ER - TY - CHAP A1 - Wenzl, Hanna A1 - Straußberger, Florian A1 - Braun, Tristan A1 - Wirtensohn, Stefan A1 - Kiltz, Lothar A1 - Reuter, Johannes A1 - Aschemann, Harald T1 - Comparison and Identifiability Analysis of Friction Models for the Dither Motion of a Solenoid T2 - 23rd International Conference on Methods Models in Automation Robotics (MMAR), 27-30 Aug. 2018, Miedzyzdroje, Poland N2 - In this paper, the mechanical subsystem of a proportional solenoid excited by a dither signal is considered. The objective is to find a suitable friction model that reflects the characteristic mechanical properties of the dynamic system. Several different friction models from the literature are compared. The friction models are evaluated with respect to their accuracy as well as their practical identifiability, the latter being quantified based on the Fisher information matrix. Y1 - 2018 SN - 978-1-5386-4325-9 U6 - http://dx.doi.org/10.1109/MMAR.2018.8485888 N1 - Volltextzugriff für Angehörige der Hochschule Konstanz via IEEE Xplore möglich. SP - 321 EP - 326 PB - IEEE ER - TY - THES A1 - Grimm, Simon T1 - Directivity Based Multichannel Audio Signal Processing For Microphones in Noisy Acoustic Environments N2 - Simon Grimm examines new multi-microphone signal processing strategies that aim to achieve noise reduction and dereverberation. Therefore, narrow-band signal enhancement approaches are combined with broad-band processing in terms of directivity based beamforming. Previously introduced formulations of the multichannel Wiener filter rely on the second order statistics of the speech and noise signals. The author analyses how additional knowledge about the location of a speaker as well as the microphone arrangement can be used to achieve further noise reduction and dereverberation. Y1 - 2018 UR - https://www.springer.com/de/book/9783658251512 SN - 978-3-658-25151-2 SN - 978-3-658-25152-9 U6 - http://dx.doi.org/10.1007/978-3-658-25152-9 PB - Springer Vieweg CY - Wiesbaden ER - TY - CHAP A1 - Safieh, Malek A1 - Thiers, Johann-Philipp A1 - Freudenberger, Jürgen T1 - Implementierung des Secure Hash Algorithmus T2 - 60. Workshop der MPC-Gruppe, 5.-6. Juli 2018, Konstanz N2 - Digitale Signaturen zum Überprüfen der Integrität von Daten, beispielsweise von Software-Updates, gewinnen zunehmend an Bedeutung. Im Bereich der eingebetteten Systeme kommen derzeit wegen der geringen Komplexität noch überwiegend symmetri-sche Verschlüsselungsverfahren zur Berechnung eines Authentifizierungscodes zum Einsatz. Asym-metrische Kryptosysteme sind rechenaufwendiger, bieten aber mehr Sicherheit, weil der Schlüssel zur Authentifizierung nicht geheim gehalten werden muss. Asymmetrische Signaturverfahren werden typischerweise zweistufig berechnet. Der Schlüssel wird nicht direkt auf die Daten angewendet, sondern auf deren Hash-Wert, der mit Hilfe einer Hash-funktion zuvor berechnet wurde. Zum Einsatz dieser Verfahren in eingebetteten Systemen ist es erforder-lich, dass die Hashfunktion einen hinreichend gro-ßen Datendurchsatz ermöglicht. In diesem Beitrag wird eine effiziente Hardware-Implementierung der SHA-256 Hashfunktion vorgestellt. Y1 - 2018 SN - 1868-9221 ER - TY - CHAP A1 - Kurth, Marcus A1 - Schleyer, Carsten A1 - Feuser, Daniel T1 - Lernfabrik BT - ein integriertes Automatisierungskonzept für die moderne Produktion in Lehre und Forschung T2 - Virtuelle Instrumente in der Praxis 2016 : Mess-, Steuer-, Regel- und Embedded-Systeme ; Begleitband zum 21. VIP-Kongress N2 - Die Einführung von cyberphysischen Systemen in der Fertigung wird die Arbeitsbedingungen und Prozesse genauso wie Geschäftsmodelle stark verändern. In der Praxis kann eine wachsende Diskrepanz zwischen Großunternehmen und KMU beobachtet werden. Genau diese Diskrepanz soll die im Folgenden präsentierte Lernfabrik überbrücken, die Unternehmen eine Plattform zum Probieren bietet, die Möglichkeit zur Ausbildung von Studenten und Mitarbeitern schafft und Beratungsangebote bereithält. Zur Umsetzung wird ein integriertes, offenes und standardisiertes Automatisierungskonzept vorgestellt, das einzelne Geräte, ganze Produktionslinien bis hin zu höheren Automatisierungssystemen umfasst und auch eine Community bereitstellt sowie zur Umsetzung neuer Geschäftsmodelle dient. KW - Industrie 4.0 KW - Cyberphysische Produkte KW - Internet of Things KW - Rapid Protoryping KW - Lean Production Y1 - 2016 UR - http://www.etz.de/files/077_kurth-schleyer-feuser.pdf SN - 978-3-8007-4208-0 SP - 413 EP - 417 ER - TY - CHAP A1 - Rohweder, Daniel A1 - Freudenberger, Jürgen A1 - Shavgulidze, Sergo T1 - Low-Density Parity-Check Codes over Finite Gaussian Integer Fields T2 - IEEE International Symposium on Information Theory (ISIT), 17-22 June 2018, Vail, CO, USA N2 - This work proposes a construction for low-density parity-check (LDPC) codes over finite Gaussian integer fields. Furthermore, a new channel model for codes over Gaussian integers is introduced and its channel capacity is derived. This channel can be considered as a first order approximation of the additive white Gaussian noise channel with hard decision detection where only errors to nearest neighbors in the signal constellation are considered. For this channel, the proposed LDPC codes can be decoded with a simple non-probabilistic iterative decoding algorithm similar to Gallager's decoding algorithm A. Y1 - 2018 UR - https://ieeexplore.ieee.org/document/8437456 U6 - http://dx.doi.org/10.1109/ISIT.2018.8437456 SN - 2157-8117 N1 - Volltextzugriff für Angehörige der Hochschule Konstanz via Datenbank IEEE Xplore möglich. SP - 481 EP - 485 ER - TY - PAT A1 - Freudenberger, Jürgen A1 - Rajab, Mohammed A1 - Baumhof, Christoph T1 - Methods and Apparatus for Error Correction Coding Based on Data Compression N2 - Embodiments are generally related to the field of channel and source coding of data to be sent over a channel, such as a communication link or a data memory. Some specific embodiments are related to a method of encoding data for transmission over a channel, a corresponding decoding method, a coding device for performing one or both of these methods and a computer program comprising instructions to cause said coding device to perform one or both of said methods. Y1 - 2018 UR - https://patentscope.wipo.int/search/en/detail.jsf?docId=US221774105 ER -