Inst. Energie- und Automatisierungstechnik

139 Items

Recent Submissions
Feedback-controlled functional electrical stimulation to restore upper extremity functions

Klauer, Christian (2019)

This thesis considers Neuro-prosthetic systems using Functional Electrical Stimulation (FES) to restore or support motor functions in neurologically impaired patients. An often encountered difficulty is the precise control of limb motion by adjusting the stimulation intensity. The musculoskeletal systems involving muscle mechanics, limb motion dynamics, and muscle recruitment due to FES and pos...

The photometry of hollow light guides

Rosemann, A. ; Kloss, S.-H. ; Müller, T. ; Aydinli, Sirri ; Kaase, Heinrich (2005)

Light-pipes described in this paper guide light along an axis allowing it to escape from its surface for illumination purposes. Light is coupled into them by a beamer luminaire. The performance of a hollow light guide very much depends on the quality of the materials used to guide the light. The luminous characteristics of these materials influence a light-pipe’s overall performance. The first ...

Experimental investigation of GaN power devices

Badawi, Nasser (2018)

Over the next decade, the power electronics will require a new generation of semiconductor devices that are smaller, cheaper and more efficient. Technology changes will radically influence the power electronics business in different industries, including the automotive, renewable energy, motion and rail industry. The key features of highly efficient power converters comprise high switching perf...

Optimal control of mobile robots in partially unknown environments

Nenchev, Vladislav (2018)

An autonomous mobile robot that performs a task in a partially unknown environment pursues two goals simultaneously: on the one hand, it has to acquire information from the environment (necessary for solving the task), and on the other hand, it must use this information to adapt its control strategy. This fundamental compromise between exploration and exploitation in motion planning has been ex...

Entwurf und Konstruktion einer vertikal laufenden Windturbine nach dem Widerstandsprinzip unter Nutzung der aerodynamischen Eigenschaften eines Flügelprofils

Sarmadi, Mohammad-Ali (2018)

Die umweltfreundlichen und geräuscharmen vertikalen Windenergieanlagen, die nach dem Widerstandsprinzip arbeiten, erzeugen ein hohes Drehmoment und sind windrichtungsunabhängig. Trotz dieser Vorteile haben sie niedrige Drehzahlen und ihre Gestalt ist massiv, so dass sie in der Höhe nicht für große Produktionen eingesetzt werden können. Gerade diese Nachteile haben es bis jetzt verhindert, dass ...

Advanced technology for gait rehabilitation: An overview

Mikolajczyk, Tadeusz ; Ciobanu, Ileana ; Badea, Doina Ioana ; Iliescu, Alina ; Pizzamiglio, Sara ; Schauer, Thomas ; Seel, Thomas ; Seiciu, Petre Lucian ; Turner, Duncan L. ; Berteanu, Mihai (2018)

Most gait training systems are designed for acute and subacute neurological inpatients. Many systems are used for relearning gait movements (nonfunctional training) or gait cycle training (functional gait training). Each system presents its own advantages and disadvantages in terms of functional outcomes. However, training gait cycle movements is not sufficient for the rehabilitation of ambulat...

Dynamische geometrische Konturmodelle zur Segmentierung intravaskulärer Ultraschallbildfolgen für die dreidimensionale Oberflächenrekonstruktion koronarer Gefäßwände

Schmauder, Martin ; Orglmeister, Reinhold ; Volk, D. ; Aldekamp, F. ; Gross, C. M. ; Waigand, J. (1998)

Im folgenden wird eine neue Methode zur Bestimmung der inneren und äußeren Gefäßwandkontur (Intima und Media) auf der Basis sagittaler IVUS-Schnittbilder vorgestellt. Die Konturen bilden die Grundlage für die dreidimensionale Rekonstruktion der Oberfläche unter Verwendung eines eigenentwickelten Systems zur SD-Darstellung intravaskulärer tomographischer Datensätze.

Ein implantierbares Telemetriesystem zur Impedanzspektroskopie

Seeger, A. ; Kertzscher, U. ; Gerhäußer, A. ; Krause, F. ; Sommer, G. ; Kolupa, J. ; Schäfer, H. ; Arnold, R. ; Affeld, K. ; Schaldach, M. ; Scheel, W. ; Orglmeister, Reinhold ; Manck, Otto (1998)

Die kontinuierliche Überwachung des intrakorporalen Zustandes von Geweben beispielsweise zur Erkennung ischämischer Vorgänge nach gefäßchirurgischen Eingriffen oder im Rahmen der Rejektionsdiagnostik läßt sich durch bisher vorhandene Meßsysteme nur bedingt erreichen. Speziell die direkte Erfassung sensitiver Gewebeparameter über einen längeren Zeitraum ohne Belastung für den Patienten stellt...

Geregelter Meßplatz für Sensoren zur invasiven Blutdruckmessung

El-Natsheh, N. ; Zerle, S. ; Köhler, B. ; Orglmeister, Reinhold (1998)

Der im vorliegenden Artikel vorgestellte neuartige Simulator ist ein kompletter Meßplatz für die Prüfung der gesamten Blutdruckmeßkette entsprechend den AAMI-Spezifikationen für alle gängigen medizinischen Drucksensoren. Mit Hilfe einer mikrocontrollergesteuerten Einheit werden gespeicherte technische Solldruckkurven einstellbarer Amplitude und Frequenz sowie physiologische Druckverläufe erzeug...

Segmentierungsbasierte Bewegungsschätzung in Ultraschallbildern

Reise, F. ; Rothlübbers, C. ; Orglmeister, Reinhold (1998)

Ein neuer Ansatz zur Verbesserung der Bewegungsschätzung in Ultraschallbildern des menschlichen Herzens wird vorgestellt. Der Ansatz nutzt den Optischen Fluß zur Bewegungsschätzung und bestimmt relevante Bildbereiche über eine Segmentierung auf Basis der Skalierungs-lndex-Methode. Vergleiche der Ergebnisse dieses Ansatzes mit den Ergebnissen konventioneller Ansätze zeigen eine deutliche Verbess...

Tag und Nacht: Gibt es Unterschiede der Richtungsabhängigkeit nicht-visueller Effekte?

Broszio, Kai ; Knoop, Martine ; Völker, Stephan (2018-09-10)

Die bisherigen Forschungsergebnisse im Bereich nicht-visueller Wirkungen des Lichts auf den Menschen lassen kein klares Kausalitätsmuster erkennen. Einer der Gründe dafür könnte in der oft unzureichenden Beschreibung der Lichtsituation liegen. Meist wird zur Beschreibung der Intensität des Stimulus die vertikale Beleuchtungsstärke am Auge genutzt. Intrinsisch-photosensitive retinale Ganglienzel...

On the perspectives of SiC MOSFETs in high-frequency and high-power isolated DC/DC converters

Eial Awwad, Abdullah (2018)

Increasing demand for efficiency and power density pushes Si-based devices to some of their inherent material limits, including those related to temperature operation, switching frequency, and blocking voltage. Recently, SiC-based power devices are promising candidates for high-power and high-frequency switching applications. Today, SiC MOSFETs are commercially available from several manufactur...

Control layout of doubly fed induction generator with respect to low voltage ride through for wind energy conversion system

Al-Quteimat, Alaa (2018)

Moving forward, the demand on renewable energy resources is increasing due to their advantages over the fossil fuels, which have harmful effects on the environment. Currently, doubly fed induction generators (DFIG) are widely used for wind turbines. Compared to other variable-speed generators; the main advantage of the DFIG is that the power electronic devices must deal with only about a third ...

Alternating current loss measurement of power cable conductors with large cross sections using electrical methods

Suchantke, René (2018)

High voltage power cables for bulk AC power transport use the Milliken conductor design from a certain cross section up to decrease transmission losses. It is not possible to reliably assess their AC losses by simulation or other calculation methods in advance, as the performance of this complex design strongly depends on manufacturing processes and quality. The exact knowledge of the AC resist...

Enhancing the smoothness of joint motion induced by functional electrical stimulation using co-activation strategies

Ruppel, Mirjana ; Klauer, Christian ; Schauer, Thomas (2017-09-07)

The motor precision of today’s neuroprosthetic devices that use artificial generation of limb motion using Functional Electrical Stimulation (FES) is generally low. We investigate the adoption of natural co-activation strategies as present in antagonistic muscle pairs aiming to improve motor precision produced by FES. In a test in which artificial knee-joint movements were generated, we could i...

In-ear photoplethysmography for central pulse waveform analysis in non-invasive hemodynamic monitoring

Tigges, Timo ; Rockstroh, Jonas ; Pielmuş, Alexandru-Gabriel ; Klum, Michael ; Feldheiser, Aarne ; Hunsicker, Oliver ; Orglmeister, Reinhold (2017)

In recent years, the analysis of the photoplethys-mographic (PPG) pulse waveforms has attracted much research focus. However, the considered signals are primarily recorded at the fingertips, which suffer from reduced peripheral perfusion in situations like hypovolemia or sepsis, rendering waveform analysis infeasible. The ear canal is not affected by cardiovascular centralization and could thus...

Correlation of arterial blood pressure to synchronous piezo, impedance and photoplethysmographic signal features

Pielmuş, Alexandru-Gabriel ; Osterland, Dennis ; Klum, Michael ; Tigges, Timo ; Feldheiser, Aarne ; Hunsicker, Oliver ; Orglmeister, Reinhold (2017)

In this paper we investigate which pulse wave pick-up technologies are well suited for blood pressure trend estimation. We use custom built hardware to acquire electrocardiographic, applanation-tonometric, photo- and impedance-plethysmographic signals during low intensity workouts. Beat-to-beat features and pulse wave runtimes are correlated to the reference arterial blood pressure. Temporal la...

Spatial sampling of a driver’s visual field: characterising peripheral adaptation

Winter, Jan-Christoph (2018)

For the application of the recommended system of mesopic photometry of the Commission Internationale d'Eclairage (CIE) in road lighting design it is necessary to estimate the peripheral state of adaptation of a driver in an urban environment after dark. Estimating the state of adaptation of a driver in the natural setting is not straightforward, because the visual scene is likely complex and i...

Stability, voltage performance and power sharing issues of inverter-based microgrids via LMI optimization

Truong, Duc Trung (2018)

Numerous small distributed energy resources (DERs) form a new generation of power systems - the microgrid. In general, a microgrid stands for a cluster of DERs, which can collectively operate as an individual low-voltage power system during islanded mode. A microgrid can also be operated in connected mode with a large power system. DERs are often interfaced to a microgrid through power electron...

Überwachung hybrider Schrägkugellager in Luftfahrttriebwerken

Lück, Rudolf (2018)

A concept to monitor hybrid angular ball bearings is presented. Interactions of damaged balls with the steel raceways are shown. Week points in calculating ball spinning speeds are discussed and methods to improve this are proposed. Results based on sensors measuring structure borne noise are compared to results of vibration sensors and metal particle sensors. It is shown that a detection of be...