TY  - JOUR
A1  - Götten, Falk
A1  - Havermann, Marc
A1  - Braun, Carsten
A1  - Gomez, Francisco
A1  - Bil, Cees
T1  - RANS Simulation Validation of a Small Sensor Turret for UAVs
JF  - Journal of Aerospace Engineering
N2  - Recent Unmanned Aerial Vehicle (UAV) design procedures rely on full aircraft steady-state Reynolds-Averaged-Navier-Stokes (RANS) analyses in early design stages. Small sensor turrets are included in such simulations, even though their aerodynamic properties show highly unsteady behavior. Very little is known about the effects of this approach on the simulation outcomes of small turrets. Therefore, the flow around a model turret at a Reynolds number of 47,400 is simulated with a steady-state RANS approach and compared to experimental data. Lift, drag, and surface pressure show good agreement with the experiment. The RANS model predicts the separation location too far downstream and shows a larger recirculation region aft of the body. Both characteristic arch and horseshoe vortex structures are visualized and qualitatively match the ones found by the experiment. The Reynolds number dependence of the drag coefficient follows the trend of a sphere within a distinct range. The outcomes indicate that a steady-state RANS model of a small sensor turret is able to give results that are useful for UAV engineering purposes but might not be suited for detailed insight into flow properties.
Y1  - 2019
U6  - https://doi.org/10.1061/(ASCE)AS.1943-5525.0001055
SN  - 1943-5525
VL  - 32
IS  - 5
PB  - ASCE
CY  - New York
ER  - 
TY  - CHAP
A1  - Rebel, Sören
A1  - Hüning, Felix
A1  - Scholl, Ingrid
A1  - Ferrein, Alexander
T1  - MQOne: Low-cost design for a rugged-terrain robot platform
T2  - Intelligent robotics and applications : 8th International Conference, ICIRA 2015, Portsmouth, UK, August 24-27, 2015, Proceedings, Part II (Lecture notes in computer science : vol. 9245)
N2  - Rugged terrain robot designs are important for field robotics missions. A number of commercial platforms are available, however, at an impressive price. In this paper, we describe the hardware and software component of a low-cost wheeled rugged-terrain robot. The robot is based on an electric children quad bike and is modified to be driven by wire. In terms of climbing properties, operation time and payload it can compete with some of the commercially available platforms, but at a far lower price.
Y1  - 2015
SN  - 978-3-319-22875-4 (print) ; 978-3-319-22876-1 (E-Book)
U6  - https://doi.org/10.1007/978-3-319-22876-1_19
SP  - 209
EP  - 221
PB  - Springer
CY  - Cham
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Low-Thrust Trajectory Optimization and Interplanetary Mission Analysis Using Evolutionary Neurocontrol
JF  - Deutscher Luft- und Raumfahrtkongress 2004 : Dresden, 20. bis 23. September 2004, Motto: Luft- und Raumfahrt - Brücke für eine wissensbasierte Gesellschaft / Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR). [Red.: Peter Brandt (verantwortlich)]. - Bd. 2. - (Jahrbuch ... der Deutschen Gesellschaft für Luft- und Raumfahrt)
Y1  - 2004
N1  - Deutscher Luft- und Raumfahrt-Kongress <2004, Dresden> ; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth ; DGLR-2004-116
SP  - 917
EP  - 926
CY  - Bonn
ER  - 
TY  - JOUR
A1  - Wolf, Martin R.
A1  - Luczak, Holger
T1  - Computer Supported Communication and Cooperation – Making Information Aware / Luczak, H. ; Wolf, M.
JF  - Human-computer interaction : proceedings of HCI International '99 (the 8th International Conference on Human-Computer Interaction), Munich, Germany, August 22 - 26, 1999
Y1  - 1999
N1  - HCI - International Conference on Human-Computer Interaction ; 8 (Munich, Germany) : 1999.08.22-26 ; in 2 Bänden
SP  - 298
EP  - 302
PB  - Erlbaum
CY  - Mahwah, NJ
ER  - 
TY  - CHAP
A1  - Nikolovski, Gjorgji
A1  - Limpert, Nicolas
A1  - Nessau, Hendrik
A1  - Reke, Michael
A1  - Ferrein, Alexander
T1  - Model-predictive control with parallelised optimisation for the navigation of autonomous mining vehicles
T2  - 2023 IEEE Intelligent Vehicles Symposium (IV)
N2  - The work in modern open-pit and underground mines requires the transportation of large amounts of resources between fixed points. The navigation to these fixed points is a repetitive task that can be automated. The challenge in automating the navigation of vehicles commonly used in mines is the systemic properties of such vehicles. Many mining vehicles, such as the one we have used in the research for this paper, use steering systems with an articulated joint bending the vehicle’s drive axis to change its course and a hydraulic drive system to actuate axial drive components or the movements of tippers if available. To address the difficulties of controlling such a vehicle, we present a model-predictive approach for controlling the vehicle. While the control optimisation based on a parallel error minimisation of the predicted state has already been established in the past, we provide insight into the design and implementation of an MPC for an articulated mining vehicle and show the results of real-world experiments in an open-pit mine environment.
KW  - Mpc
KW  - Control
KW  - Path-following
KW  - Navigation
KW  - Automation
Y1  - 2023
SN  - 979-8-3503-4691-6 (Online)
SN  - 979-8-3503-4692-3 (Print)
U6  - https://doi.org/10.1109/IV55152.2023.10186806
N1  - IEEE Symposium on Intelligent Vehicle, 4.-7. June 2023, Anchorage, AK, USA.
PB  - IEEE
ER  - 
TY  - JOUR
A1  - Loeb, Horst Wolfgang
A1  - Schartner, Karl-Heinz
A1  - Dachwald, Bernd
A1  - Ohndorf, Andreas
A1  - Seboldt, Wolfgang
T1  - Interstellar heliopause probe
JF  - Труды МАИ
N2  - There is common agreement within the scientific community that in order to understand our local galactic environment it will be necessary to send a spacecraft into the region beyond the solar wind termination shock. Considering distances of 200 AU for a new mission, one needs a spacecraft traveling at a speed of close to 10 AU/yr in order to keep the mission duration in the range of less than 25 yrs, a transfer time postulated by European Space Agency (ESA). Two propulsion options for the mission have been proposed and discussed so far: the solar sail propulsion and the ballistic/radioisotope-electric propulsion (REP). As a further alternative, we here investigate a combination of solar-electric propulsion (SEP) and REP. The SEP stage consists of six 22-cms diameter RIT-22 ion thrusters working with a high specific impulse of 7377 s corresponding to a positive grid voltage of 5 kV. Solar power of 53 kW at begin of mission (BOM) is provided by a lightweight solar array.
Y1  - 2012
IS  - 60
SP  - 2
EP  - 2
PB  - Moskauer Staatliches Luftfahrtinstitut (МАИ)
CY  - Moskau
ER  - 
TY  - CHAP
A1  - Capitain, C.
A1  - Hering, T.
A1  - Tippkötter, Nils
A1  - Ulber, Roland
T1  - Enzymatic polymerization of lignin model compounds and solubilized lignin in an aqueous ethanol extract
T2  - New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany
Y1  - 2016
SP  - 151
EP  - 152
PB  - DECHEMA
CY  - Frankfurt am Main
ER  - 
TY  - CHAP
A1  - Duong, Minh Tuan
A1  - Nguyen, Nhu Huynh
A1  - Staat, Manfred
ED  - Eberhardsteiner, J.
T1  - Numerical stability enhancement of modeling hyperelastic materials
T2  - Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)
Y1  - 2012
N1  - 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012
ER  - 
TY  - JOUR
A1  - Pogorelova, Natalia
A1  - Rogachev, Evgeniy
A1  - Digel, Ilya
A1  - Chernigova, Svetlana
A1  - Nardin, Dmitry
T1  - Bacterial Cellulose Nanocomposites: Morphology and Mechanical Properties
JF  - Materials
N2  - Bacterial cellulose (BC) is a promising material for biomedical applications due to its unique properties such as high mechanical strength and biocompatibility. This article describes the microbiological synthesis, modification, and characterization of the obtained BC-nanocomposites originating from symbiotic consortium Medusomyces gisevii. Two BC-modifications have been obtained: BC-Ag and BC-calcium phosphate (BC-Ca3(PO4)2). Structure and physicochemical properties of the BC and its modifications were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and infrared Fourier spectroscopy as well as by measurements of mechanical and water holding/absorbing capacities. Topographic analysis of the surface revealed multicomponent thick fibrils (150–160 nm in diameter and about 15 µm in length) constituted by 50–60 nm nanofibrils weaved into a left-hand helix. Distinctive features of Ca-phosphate-modified BC samples were (a) the presence of 500–700 nm entanglements and (b) inclusions of Ca3(PO4)2 crystals. The samples impregnated with Ag nanoparticles exhibited numerous roundish inclusions, about 110 nm in diameter. The boundaries between the organic and inorganic phases were very distinct in both cases. The Ag-modified samples also showed a prominent waving pattern in the packing of nanofibrils. The obtained BC gel films possessed water-holding capacity of about 62.35 g/g. However, the dried (to a constant mass) BC-films later exhibited a low water absorption capacity (3.82 g/g). It was found that decellularized BC samples had 2.4 times larger Young’s modulus and 2.2 times greater tensile strength as compared to dehydrated native BC films. We presume that this was caused by molecular compaction of the BC structure.
Y1  - 2020
SN  - 1996-1944
U6  - https://doi.org/10.3390/ma13122849
VL  - 13
IS  - 12
SP  - 1
EP  - 16
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Göttsche, Joachim
A1  - Alexopoulos, Spiros
A1  - Dümmler, Andreas
A1  - Maddineni, S. K.
T1  - Multi-Mirror Array Calculations With Optical Error
N2  - The optical performance of a 2-axis solar concentrator was simulated with the COMSOL Multiphysics® software. The concentrator consists of a mirror array, which was created using the application builder. The mirror facets are preconfigured to form a focal point. During tracking all mirrors are moved simultaneously in a coupled mode by 2 motors in two axes, in order to keep the system in focus with the moving sun. Optical errors on each reflecting surface were implemented in combination with the solar angular cone of ± 4.65 mrad. As a result, the intercept factor of solar radiation that is available to the receiver was calculated as a function of the transversal and longitudinal angles of incidence. In addition, the intensity distribution on the receiver plane was calculated as a function of the incidence angles.
KW  - solar process heat
KW  - concentrating collector
KW  - raytracing
KW  - point-focussing system
Y1  - 2019
SP  - 1
EP  - 6
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
A1  - Richter, L.
T1  - Multiple Rendezvous and Sample Return Missions to Near-Earth Asteroids Using Solar Sailcraft
JF  - Proceedings of the Fifth IAA International Conference on Low Cost Planetary Missions : 24 - 26 September 2003, ESTEC, Noordwijk, the Netherlands / [comp. by R. A. Harris]
Y1  - 2003
SN  - 92-9092-853-0
N1  - International Conference on Low Cost Planetary Missions <5, 2003, Noordwijk> ; International Academy of Astronautics ; European Space Research and Technology Centre
SP  - 351
EP  - 358
PB  - ESA
CY  - Noordwijk
ER  - 
TY  - CHAP
A1  - Becker, Jörg
A1  - Eggert, Mathias
A1  - Heddier, Marcel
A1  - Knackstedt, Ralf
T1  - Merging Conceptual Modeling and Law for Legally Compliant Information Systems Design - A Framework-Based Research Agenda
T2  - 45th Hawaii International Conference on System Sciences 2012
Y1  - 2012
SN  - 978-0-7695-4525-7
U6  - https://doi.org/10.1109/HICSS.2012.428
SP  - 5241
EP  - 5248
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
A1  - Dylla, Frank
A1  - Lakemeyer, Gerhard
A1  - Murray, Jan
T1  - Approaching a formal soccer theory from behaviour specifications in robotic soccer / Dylla, Frank ; Ferrein, Alexander ; Lakemeyer, Gerhard ; Murray, Jan ; Obst, Oliver ; Röfer, Thomas ; Schiffer, Stefan ; Stolzenburg, Frieder ; Visser, Ubbo ; Wagner, Tho
JF  - Computers in sport / editors: P Dabnichki
Y1  - 2008
SN  - 978-1-8456-4064-4
SP  - 161
EP  - 185
PB  - WIT Press
CY  - Southampton
ER  - 
TY  - CHAP
A1  - Eichler, Fabian
A1  - Skupin, Marco
A1  - Thurn, Laura
A1  - Kasch, Susanne
A1  - Schmidt, Thomas
T1  - Operating limits for beam melting of glass materials
T2  - Modern Technologies in Manufacturing (MTeM 2019)
N2  - Laser-based Additive Manufacturing (AM) processes for the use of metals out of the powder bed have been investigated profusely and are prevalent in industry. Although there is a broad field of application, Laser Powder Bed Fusion (LPBF), also known as Selective Laser Melting (SLM) of glass is not fully developed yet. The material properties of glass are significantly different from the investigated metallic material for LPBF so far. As such, the process cannot be transferred, and the parameter limits and the process sequence must be redefined for glass. Starting with the characterization of glass powders, a parameter field is initially confined to investigate the process parameter of different glass powder using LPBFprocess. A feasibility study is carried out to process borosilicate glass powder. The effects of process parameters on the dimensional accuracy of fabricated parts out of borosilicate and hints for the post-processing are analysed and presented in this paper.
Y1  - 2019
U6  - https://doi.org/10.1051/matecconf/201929901004
N1  - MATEC Web of Conferences 299; MTeM 2019
VL  - 299
IS  - Article 01004
ER  - 
TY  - JOUR
A1  - Hackl, M.
A1  - Andermahr, J.
A1  - Staat, Manfred
A1  - Bremer, I.
A1  - Borggrefe, J.
A1  - Prescher, A.
A1  - Müller, L. P.
A1  - Wegmann, K.
T1  - Suture button reconstruction of the central band of the interosseous membrane in Essex-Lopresti lesions: a comparative biomechanical investigation
JF  - The Journal of Hand Surgery (European Volume)
Y1  - 2017
U6  - https://doi.org/10.1177/1753193416665943
SN  - 2043-6289 (Online)
SN  - 1753-1934 (Print)
VL  - 42
IS  - 4
SP  - 370
EP  - 376
PB  - Sage
CY  - London
ER  - 
TY  - JOUR
A1  - Göddeke, Dominik
A1  - Strzodka, Robert
A1  - Mohd-Yusof, Jamaludin
A1  - McCormick, Patrick
A1  - Buijssen, Sven H.M.
A1  - Grajewski, Matthias
A1  - Turek, Stefan
T1  - Exploring weak scalability for FEM calculations on a GPU-enhanced cluster
JF  - Parallel Computing
Y1  - 2007
U6  - https://doi.org/10.1016/j.parco.2007.09.002
SN  - 0167-8191
VL  - 33
IS  - 10-11
SP  - 685
EP  - 699
ER  - 
TY  - JOUR
A1  - Booysen, Tracy
A1  - Rieger, Michael
A1  - Ferrein, Alexander
T1  - Towards inexpensive robots for science & technology teaching and education in Africa
Y1  - 2011
SN  - 978-1-61284-992-8
N1  - AFRICON, 2011
SP  - 1
EP  - 6
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Stulpe, Werner
A1  - Hellwig, K.-E.
T1  - A Classical Reformulation of Finite-Dimensional Quantum Mechanics. Hellwig, K.-E.; Stulpe, W.
JF  - Quantum measurement, irreversibility and the physics of information / Symposium on the Foundations of Modern Physics 1993, Cologne, Germany 1 - 5 June 1993. Ed. Paul Busch
Y1  - 1993
SN  - 981021507X
N1  - Symposium on the Foundations of Modern Physics ; <1993, Köln>
SP  - 209
EP  - 214
PB  - World Scientific
CY  - Singapore [u.a.]
ER  - 
TY  - CHAP
A1  - Ferrein, Alexander
A1  - Maier, Christopher
A1  - Mühlbacher, Clemens
A1  - Niemueller, Tim
A1  - Steinbauer, Gerald
A1  - Vassos, Stravros
T1  - Controlling Logistics Robots with the Action-based Language YAGI
T2  - Proceedings of the 2015 IROS Workshop on Workshop on Task Planning for Intelligent Robots in Service and Manufacturing
Y1  - 2015
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - LISA - a European project for FEM-based limit and shakedown analysis
N2  - The load-carrying capacity or the safety against plastic limit states are the central questions in the design of structures and passive components in the apparatus engineering. A precise answer is most simply given by limit and shakedown analysis. These methods can be based on static and kinematic theorems for lower and upper bound analysis. Both may be formulated as optimization problems for finite element discretizations of structures. The problems of large-scale analysis and the extension towards realistic material modelling will be solved in a European research project. Limit and shakedown analyses are briefly demonstrated with illustrative examples.
KW  - Einspielen <Werkstoff>
KW  - Traglast
KW  - Finite-Elemente-Methode
KW  - Traglastanalyse
KW  - Einspielanalyse
KW  - FEM
KW  - limit analysis
KW  - shakedown analysis
Y1  - 2001
ER  -