Fachbereich Elektrotechnik, Maschinenbau, Technikjournalismus
Refine
Department, Institute
- Fachbereich Elektrotechnik, Maschinenbau, Technikjournalismus (339)
- Institut für Technik, Ressourcenschonung und Energieeffizienz (TREE) (135)
- Institute of Visual Computing (IVC) (36)
- Fachbereich Informatik (25)
- Internationales Zentrum für Nachhaltige Entwicklung (IZNE) (15)
- Fachbereich Wirtschaftswissenschaften (5)
- Fachbereich Angewandte Naturwissenschaften (4)
- Institut für funktionale Gen-Analytik (IfGA) (4)
- Verwaltung (3)
- Institut für Medienentwicklung und -analyse (IMEA) (2)
Document Type
- Conference Object (145)
- Article (121)
- Part of a Book (21)
- Book (20)
- Report (14)
- Preprint (7)
- Contribution to a Periodical (3)
- Doctoral Thesis (2)
- Lecture (2)
- Other (1)
Year of publication
Language
- English (210)
- German (126)
- Spanish (2)
- Multiple languages (1)
Keywords
- FPGA (9)
- Education (5)
- ISM: molecules (5)
- education (5)
- Lehrbuch (4)
- Method of lines (4)
- Force field (3)
- bolometers (3)
- digital design (3)
- efficiency (3)
Error analysis in a high accuracy sampled-data velocity stabilising system using Volterra series
(2015)
The paper presents a new method of analysis of error in a sampled-data velocity stabilising system operating under wide range pulse width modulation. The analysis is based on multi-channel model of the system obtained as a result of approximation of pulse-modulated signal from the output of a PWM converter. Approximation of piecewise-linear modulation characteristics of each channel was obtained as a series expansion of Hermite polynomials where the expansion comprises two polynomials of the first and third orders. Transfer functions of each channel and a closed-loop system were obtained using a multidimensional Z-transform based on Volterra series. The analytical expression of error under impact of a step input was derived using the transfer function of the closed-loop system. A DC electric drive was used as an example of high accuracy sample-data stabilising system in order to simulate and verify the proposed method.
This paper presents a new method of analysing the error of a sampled-data velocity stabilising system with a wide range of pulse width modulation. The analysis is based on multi-channel model obtained as a result of approximation of pulse-modulated signal at the output of a PWM converter. Approximation of piecewise-linear modulation characteristics of each channel has been obtained as a series expansion of Hermite polynomials where the expansion comprises two polynomials of the first and third orders. The transfer function of every channel and a closed-loop system has been obtained using multidimensional Z-transform. The analytical expression of an error under impact of a step input has been derived using a transfer function of the closed-loop system. A dc electric drive has been used as an example of high accuracy sample-data stabilising system to verify and demonstrate the proposed method.
This paper presents a new method of analysing the error of a sampled-data velocity stabilising system with a wide range of pulse width modulation. The analysis is based on multi-channel model obtained as a result of approximation of pulse-modulated signal at the output of a PWM converter. Approximation of piecewise-linear modulation characteristics of each channel has been obtained as a series expansion of Hermite polynomials where the expansion comprises two polynomials of the first and third orders. The transfer function of every channel and a closed-loop system has been obtained using multidimensional Z-transform. The analytical expression of an error under impact of a step input has been derived using a transfer function of the closed-loop system. A dc electric drive has been used as an example of high accuracy sample-data stabilising system to verify and demonstrate the proposed method.
Microwave Kinetic Inductance Detectors have great potential for large very sensitive detector arrays for use in, for example, ground and spaced based sub?mm imaging. Being intrinsically readout in the frequency domain, they are particularly suited for frequency domain multiplexing allowing 1000s of devices to be readout with one pair of coaxial cables. However, this moves the complexity of the detector from the cryogenics to the warm electronics. We present the use of a readout based on a Fast Fourier transform Spectrometer, showing no deterioration of the noise performance compared to low noise analog mixing while allowing high multiplexing ratios (>100). We present use of this technique to multiplex 44 MKIDs, while this and similar setups are regularly now being used in our array development. This development will help the realization of large cameras, particularly in the short term for ground based astronomy.
Microwave kinetic inductance detectors have great potential for large, very sensitive detector arrays for use in, for example, submillimeter imaging. Being intrinsically readout in the frequency domain, they are particularly suited for frequency domain multiplexing allowing ?1000s of devices to be readout with one pair of coaxial cables. However, this moves the complexity of the detector from the cryogenics to the warm electronics. We present here the concept and experimental demonstration of the use of fast Fourier transform spectrometer readout, showing no deterioration of the noise performance compared to the low noise analog mixing while allowing high multiplexing ratios.
With the GREAT receiver at the Stratospheric Observatory for Infrared Astronomy (SOFIA), nine massive molecular clumps have been observed in the ammonia 32+−22− line at 1.8 THz in a search for signatures of infall. The sources were selected from the ATLASGAL submillimeter dust continuum survey of our Galaxy. Clumps with high masses covering a range of evolutionary stages based on their infrared properties were chosen. The ammonia line was detected in all sources, leading to five new detections and one confirmation of a previous detection of redshifted absorption in front of their strong THz continuum as a probe of infall in the clumps. These detections include two clumps embedded in infrared dark clouds. The measured velocity shifts of the absorptions compared to optically thin C17O (3–2) emission are 0.3–2.8 km s-1, corresponding to fractions of 3% to 30% of the free-fall velocities of the clumps. The ammonia infall signature is compared with complementary data of different transitions of HCN, HNC, CS, and HCO+, which are often used to probe infall because of their blue-skewed line profiles. The best agreement with the ammonia results is found for the HCO+ (4–3) transitions, but the latter is still strongly blended with emission from associated outflows. This outflow signature is far less prominent in the THz ammonia lines, which confirms it as a powerful probe of infall in molecular clumps. Infall rates in the range from 0.3 to 16 × 10-3 M⊙/yr were derived with a tentative correlation with the virial parameters of the clumps. The new observations show that infall on clump scales is ubiquitous through a wide range of evolutionary stages, from L/M covering about ten to several hundreds.
The Project SupraMetall: Towards Commercial Fabrication of High-Temperature Superconducting Tapes
(2014)
The aim of the joint industrial and academic project “SupraMetall” is to enable the large scale production of superconducting tapes. This is a report of the recent achievements in the production of cube textured metal substrates and the coating techniques of the buffer and superconductive layers. The final coated conductor tapes of 2 m length reached critical current densities of 120 A/cm-width.
Ausgangspunkt der im Folgenden vorgestellten Semesterstruktur war die Umstellung der vorhandenen Diplomstudiengänge auf den Bachelor-Abschluss. Am Fachbereich werden drei grundständige Studiengänge angeboten; die technischen Studiengänge Elektrotechnik und Maschinenbau sowie der interdisziplinäre Studiengang Technikjournalismus, der den Geistes- und Sozialwissenschaften zuzurechnen ist. Ebenfalls sind duale Studiengänge vorhanden, die an grundständige Studiengänge angelehnt sind.
Education in low-power digital design is a topic within the context of a state-of-the-art electrical engineering curriculum. In this contribution, a development board for use in hands-on lab experiments on power dissipation in digital circuits is described. This board can send a video signal to a field-programmable gate array (FPGA), which students can then program using various signal processing applications. Implementations with different complexity and circuit structures and their power dissipation can be comparatively observed by the students. A prototype of this development board is being manufactured and will be used in hands-on laboratory sessions and projects.
Rendering of virtual scenes is an application that still demands higher computing power for more complex and more realistic scenes. In addition to existing parallel processing inside a graphics processing unit, this paper investigates a further level of parallelization. A combiner based on an FPGA (field programmable gate array) allows to merge the graphics output of several independent computers. The image combiner supports different load distribution techniques, namely sort-first and sort-last rendering. A system prototype based on a commercial evaluation system proved the viability of the approach. A compact and cost-efficient dedicated implementation has been designed and is used as a platform to investigate different approaches for parallel rendering.
A basic understanding of technology is recognized as important knowledge for students outside engineering and computer science. This paper shows that also embedded system concepts can be taught in a technological literacy course. An embedded system teaching block is presented that has been used in an electronics module for non-engineers. It uses one hour of lecturing and three hours of hands-on lab work. Feedback during the lab and an evaluation show that students can gain basic understanding of the topic even in such a limited time.
A basic understanding of technology is recognized as important knowledge even for students not connected with engineering and computer science. This paper shows that embedded system concepts can be taught in a technological literacy course. An embedded system teaching block that has been used in an electronics module for non-engineers is presented. It comprises 1 h of lecturing and 3 h of hands-on lab work. Feedback and evaluation show that students are able to gain a basic understanding of the topic even in such a limited time.
Seit 2012 wird an der Hochschule Bonn-Rhein-Sieg die Studieneingangsphase im Qualitätspakt Lehre gefördert. Ein wesentliches Anliegen im Projekt „Pro-MINT-us“ ist die Einbeziehung der gesamten Hochschule, um keine isolierten Maßnahmen anzubieten, sondern die im Projekt entwickelten Lehrideen nachhaltig zu verankern.
Guest lecturers from a different country can be very beneficial as students get a broader view on a subject and learn about applications not common in their home country. However, the cost and time required for traveling is a drawback. This contribution describes the exchange of teaching content between Germany and Argentina based on an e-learning approach. Short lectures are recorded on video and supplement the teaching of the local lecturer. The teaching content addresses digital logic design with FPGAs and is targeted to advanced students. The video lectures introduce an image processing algorithm for driver assistance in modern cars, which is a motivating application for students. The remote-lab allows the students to perform lab exercises with real hardware. The topic of lane detection for driver assistance is a specific application. The video lectures correspond to 1 or 2 weeks of teaching and can be used as a supplement for an existing course on digital design, FPGAs or signal processing.
An electronic display often has to present information from several sources. This contribution reports about an approach, in which programmable logic (FPGA) synchronises and combines several graphics inputs. The application area is computer graphics, especially rendering of large 3D models, which is a computing intensive task. Therefore, complex scenes are generated on parallel systems and merged to give the requested output image. So far, the transportation of intermediate results is often done by a local area network. However, as this can be a limiting factor, the new approach removes this bottleneck and combines the graphic signals with an FPGA.
Improving the study entry supports students in a decisive phase of their university education. Implementing improvements is a change process and can only be successful if the relevant stakeholders are addressed and convinced. In the described Teaching Quality Pact project evaluation data is used as a mean to discuss in the university the situation of the study programs. As these discussions were based on empirical data rather than on opinion, it was possible to achieve an open discussion about measures that are implemented. The open discussion is maintained during the project when results of the measures taken are analyzed.
Power consumption in digital circuits has been a research topic since the 1990s, and has been of significant importance in industry since at least 2000. This contribution investigates power consumption in engineering education by means of a systematic review; to determine the extent to which recent introductory textbooks on digital design address this topic. English and German textbooks that have been published since 2011 are selected, and their tables of contents are examined for the presence of sections or subsections on the topic of power consumption. A total of twenty-four textbooks match the inclusion criteria of our systematic review and, of these books, about 40% cover power dissipation in digital circuits. Thus, a significant number of authors regard power consumption as an important topic even for an introductory text. However, most authors devote only one or two pages to the topic of power dissipation, and 60% of the authors do not have a subsection on it. Therefore, a more thorough coverage of low-power design and implementation choices is often designated as supplementary material or more specialized textbooks are recommended.
Elektronik für Entscheider
(2017)
Dieses Buch gibt Nichtingenieuren, die sich beruflich mit Elektronik beschäftigen, die Möglichkeit, sich ein Stück auf dieses Fachgebiet zu begeben, um Aufgaben, Sprache und Vorgehensweise von Ingenieuren zu verstehen. Ziel ist es dabei nicht, nach dem Lesen dieses Buches eine elektronische Schaltung entwickeln zu können. Im Vordergrund steht vielmehr ein generelles Verständnis für die Zusammenhänge und Grundbegriffe der Elektronik.
Low power dissipation is a current topic in digital design, and therefore, it should be covered in a state-of-the-art electrical engineering curriculum. This paper describes how low-power design can be addressed within a digital design course. Doing so would be beneficial for both topics because low-power design is not detached from the systems perspective, and the digital design course would be enriched by references to current challenges and applications. Thus, the presented course should serve as an example of how a course can be developed to also teach students about sustainable engineering.
Low power dissipation is a current topic in digital design, and therefore, it should be covered in a state-of-the-art electrical engineering curriculum. This paper describes how low-power design can be addressed within a digital design course. Doing so would be beneficial for both topics because low-power design is not detached from the systems perspective, and the digital design course would be enriched by references to current challenges and applications. Thus, the presented course should serve as an example of how a course can be developed to also teach students about sustainable engineering.
