TY - JOUR A1 - Dachwald, Bernd T1 - Optimization of Interplanetary Solar Sailcraft Trajectories Using Evolutionary Neurocontrol JF - Journal of guidance, control, and dynamics. 27 (2004), H. 1 Y1 - 2004 SN - 0162-3192 N1 - 2. ISSN: 0162-3192. - 3. ISSN: 0731-5090 SP - 66 EP - 72 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Ohndorf, A. A1 - Gill, E. T1 - Optimization of low-thrust Earth-Moon transfers using evolutionary neurocontrol / Ohndorf, A. ; Dachwald, B. ; Gill, E. JF - IEEE Congress on Evolutionary Computation, 2009. CEC '09. Y1 - 2009 SN - 978-1-4244-2958-5 SP - 358 EP - 364 ER - TY - JOUR A1 - Dachwald, Bernd T1 - Optimization of very-low-thrust trajectories using evolutionary neurocontrol JF - Acta Astronautica N2 - Searching optimal interplanetary trajectories for low-thrust spacecraft is usually a difficult and time-consuming task that involves much experience and expert knowledge in astrodynamics and optimal control theory. This is because the convergence behavior of traditional local optimizers, which are based on numerical optimal control methods, depends on an adequate initial guess, which is often hard to find, especially for very-low-thrust trajectories that necessitate many revolutions around the sun. The obtained solutions are typically close to the initial guess that is rarely close to the (unknown) global optimum. Within this paper, trajectory optimization problems are attacked from the perspective of artificial intelligence and machine learning. Inspired by natural archetypes, a smart global method for low-thrust trajectory optimization is proposed that fuses artificial neural networks and evolutionary algorithms into so-called evolutionary neurocontrollers. This novel method runs without an initial guess and does not require the attendance of an expert in astrodynamics and optimal control theory. This paper details how evolutionary neurocontrol works and how it could be implemented. The performance of the method is assessed for three different interplanetary missions with a thrust to mass ratio <0.15mN/kg (solar sail and nuclear electric). Y1 - 2005 SN - 1879-2030 VL - 57 IS - 2-8 SP - 175 EP - 185 PB - Elsevier CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Dachwald, Bernd T1 - Optimization of very-low-thrust trajectories using evolutionary neurocontrol JF - Acta Astronautica. 57 (2005), H. 2-8 Y1 - 2005 SN - 0094-5765 SP - 175 EP - 185 ER - TY - JOUR A1 - Esch, Thomas T1 - Optimized design of the lubrication system of modern combustion engines. Verbesserte Ausführung von Schmierungssystemen bei modernen Verbrennungsmotoren Y1 - 1991 SN - 0148-7191 U6 - https://doi.org/10.4271/912407 N1 - Konferenz-Einzelbericht : SAE technical papers / Society of Automotive Engineers, Paper-Nr. 912407 SP - 1 EP - 11 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Carnelli, I. A1 - Vasile, M. T1 - Optimizing low-thrust gravity assist interplanetary trajectories using evolutionary neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile JF - IEEE Congress on Evolutionary Computation, 2007 : CEC 2007 ; 25 - 28 September 2007, Singapore Y1 - 2007 SN - 978-1-424-41339-3 N1 - ISBN 10: 1-424-41339-7 ; IEEE Congress on Evolutionary Computation <2007, Singapore> ; Institute of Electrical and Electronics Engineers ; Nebent: CEC 2007 ; Parallel als Online-Ausg. erschienen SP - 965 EP - 972 PB - IEEE Service Center CY - Piscataway, NJ ER - TY - JOUR A1 - Wittmann, Klaus T1 - Overview of Space Operations at DLR Y1 - 2000 N1 - SpaceOps2000 Conference, Toulouse, Frankreich,19-23 June 2000 ER - TY - CHAP A1 - Mathiak, Gerhard A1 - Plescher, Engelbert A1 - Willnecker, Rainer T1 - Parabolic flight experiments about vibrational effects on diffusion experiments T2 - 54th International Astronautical Congress of the International Astronautical Federation (IAF) : Bremen, 29 Sept. 2003 through 3 Oct. 2003 ; vol. 1 Y1 - 2003 SP - 4389 EP - 4396 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Mengali, Giovanni A1 - Quarta, Alessandrao A. A1 - Macdonald, Malcolm T1 - Parametric Model and Optimal Control of Solar Sails with Optical Degradation JF - Journal of guidance, control, and dynamics. 29 (2006), H. 5 Y1 - 2006 SN - 0162-3192 N1 - 2. ISSN: 0731-5090 SP - 1170 EP - 1178 ER - TY - JOUR A1 - Funke, Harald A1 - Recker, E. A1 - Bosschaerts, W. A1 - Boonen, Q. A1 - Börner, Sebastian T1 - Parametrical study of the „Micromix“ hydrogen combustion principle JF - 10th International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows, ISAIF10-049, Brussels, Belgium, 4-7 July 2011 Y1 - 2011 ER - TY - BOOK A1 - Havermann, Marc T1 - Particle image velocimetry (PIV) applied to high-speed shock tunnel flows / 23rd International Symposium on Shock Waves, Fort Worth/TX, USA, July 22 - 27, 2001. Institut Franco-Allemand de Recherches de Saint-Louis. Havermann, M. ... Y1 - 2001 N1 - International Symposium on Shock Waves 23, 2001, Fort Worth, Tex.; Publication / Institut Franco-Allemand de Recherches de Saint-Louis ; 640 PB - ISL CY - Saint-Louis ER - TY - JOUR A1 - Havermann, Marc A1 - Haertig, J. A1 - Rey, C. A1 - George, A. T1 - Particle image velocimetry in mach 3.5 and 4.5 shock-tunnel flows / Haertig, J. ; Havermann, M. ; Rey, C. ; George, A. JF - AIAA journal. 40 (2002), H. 6 Y1 - 2002 SN - 0001-1452 N1 - Printausgabe in der Bereichsbibliothek Eupener Str. Signatur: 23 Z 701 SP - 1056 EP - 1060 PB - - ER - TY - GEN A1 - Reiswich, Martin A1 - Brandt, Hannes A1 - Czupalla, Markus T1 - Passive thermal control by integration of phase change material into additively manufactured structures T2 - E2. 47th Student conference N2 - Optical Instruments require an extremely stable thermal surrounding to prevent loss of data quality by misalignments of the instrument components resulting from material deformation due to temperature f luctuations (e.g. from solar intrusion). Phase Change Material (PCM) can be applied as a thermal damper to achieve a more uniform temperature distribution. The challenge of this method is, among others, the integration of PCM into affected areas. If correctly designed, incoming heat is latently absorbed during phase change of the PCM, i.e. the temperature of a structure remains almost constant. In a cold phase, the heat during phase change is released again latently until the PCM returns to its original state of aggregation. Thus, the structure is thermally stabilized. At FH Aachen– University of Applied Sciences research is conducted to apply PCM directly into the structures of affected components (baffles, optical benches, electronic boxes, etc.). Through the application of Additive Manufacturing, the necessary voids are directly printed into these structures and filled later with PCM. Additive Manufacturing enables complex structures that would not have been possible with conservative manufacturing methods. A corresponding Breadboard was developed and manufactured by Selective Laser Melting (SLM). The current state of research includes the handling and analysis of the Breadboard, tests and a correlation of the thermal model. The results have shown analytically and practically that it is possible to use PCM as an integral part of the structure as a thermal damper. The results serve as a basis for the further development of the technology, which should maximize performance and enable the integration of PCM into much more complex structures. Y1 - 2019 N1 - 70th International Astronautical Congress, 21. - 25. Oktober 2019, Washington D.C., United States ER - TY - JOUR A1 - Spietz, Peter A1 - Spröwitz, Tom A1 - Seefeldt, Patric A1 - Grundmann, Jan Thimo A1 - Jahnke, Rico A1 - Mikschl, Tobias A1 - Mikulz, Eugen A1 - Montenegro, Sergio A1 - Reershemius, Siebo A1 - Renger, Thomas A1 - Ruffer, Michael A1 - Sasaki, Kaname A1 - Sznajder, Maciej A1 - Tóth, Norbert A1 - Ceriotti, Matteo A1 - Dachwald, Bernd A1 - Macdonald, Malcolm A1 - McInnes, Colin A1 - Seboldt, Wolfgang A1 - Quantius, Dominik A1 - Bauer, Waldemar A1 - Wiedemann, Carsten A1 - Grimm, Christian D. A1 - Hercik, David A1 - Ho, Tra-Mi A1 - Lange, Caroline A1 - Schmitz, Nicole T1 - Paths not taken – The Gossamer roadmap’s other options JF - Advances in Space Research KW - Solar sail KW - Small spacecraft KW - DLR-ESTEC GOSSAMER roadmap for solar sailing KW - GOSSAMER-1 Y1 - 2021 U6 - https://doi.org/10.1016/j.asr.2021.01.044 SN - 0273-1177 VL - 67 IS - 9 SP - 2912 EP - 2956 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Scholz, Christina A1 - Romagnoli, Daniele A1 - Dachwald, Bernd A1 - Theil, Stephan T1 - Performance analysis of an attitude control system for solar sails using sliding masses JF - Advances in Space Research Y1 - 2011 SN - 0273-1177 VL - 48 IS - 11 SP - 1822 EP - 1835 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Havermann, Marc A1 - Beylich, A. E. T1 - Performance and Limitations of the Laser-Induced Fluorescence Measurement Technique and the Established Experimental Methods for the Study of Supersonic Mixing / Havermann, M. ; Beylich, A. E. JF - International Journal of heat and technology. 15 (1997), H. 2 Y1 - 1997 SP - 3 EP - 10 PB - - ER - TY - GEN A1 - Feldmann, Marco A1 - Francke, Gero A1 - Espe, Clemes A1 - Chen, Qian A1 - Baader, Fabian A1 - Boxberg, Marc S. A1 - Sustrate, Anna-Marie A1 - Kowalski, Julia A1 - Dachwald, Bernd T1 - Performance data of an ice-melting probe from field tests in two different ice environments N2 - This dataset was acquired at field tests of the steerable ice-melting probe "EnEx-IceMole" (Dachwald et al., 2014). A field test in summer 2014 was used to test the melting probe's system, before the probe was shipped to Antarctica, where, in international cooperation with the MIDGE project, the objective of a sampling mission in the southern hemisphere summer 2014/2015 was to return a clean englacial sample from the subglacial brine reservoir supplying the Blood Falls at Taylor Glacier (Badgeley et al., 2017, German et al., 2021). The standardized log-files generated by the IceMole during melting operation include more than 100 operational parameters, housekeeping information, and error states, which are reported to the base station in intervals of 4 s. Occasional packet loss in data transmission resulted in a sparse number of increased sampling intervals, which where compensated for by linear interpolation during post processing. The presented dataset is based on a subset of this data: The penetration distance is calculated based on the ice screw drive encoder signal, providing the rate of rotation, and the screw's thread pitch. The melting speed is calculated from the same data, assuming the rate of rotation to be constant over one sampling interval. The contact force is calculated from the longitudinal screw force, which es measured by strain gauges. The used heating power is calculated from binary states of all heating elements, which can only be either switched on or off. Temperatures are measured at each heating element and averaged for three zones (melting head, side-wall heaters and back-plate heaters). KW - Ocean Worlds KW - Icy Moons KW - Cryobot KW - Analogue Environments KW - Melting Efficiency KW - Melting Performance KW - Melting Probe KW - Ice Melting Y1 - 2022 U6 - https://doi.org/10.5281/zenodo.6094866 N1 - Forschungsdaten zu "Field-test performance of an ice-melting probe in a terrestrial analogue environment" (https://opus.bibliothek.fh-aachen.de/opus4/frontdoor/index/index/docId/10889) ER - TY - CHAP A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang A1 - Häusler, Bernd T1 - Performance requirements for near-term interplanetary solar sailcraft missions T2 - 6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century N2 - Solar sailcraft provide a wide range of opportunities for high-energy low-cost missions. To date, most mission studies require a rather demanding performance that will not be realized by solar sailcraft of the first generation. However, even with solar sailcraft of moderate performance, scientifically relevant missions are feasible. This is demonstrated with a Near Earth Asteroid sample return mission and various planetary rendezvous missions. Y1 - 2002 N1 - 6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century, Versailles, France, 14-16 May 2002 ER - TY - CHAP A1 - Röth, Thilo A1 - Pielen, Michael T1 - Personal Public Vehicle – ein urbanes Fahrzeugkonzept für die „Shared Mobility“ der Zukunft T2 - Karosseriebautage Hamburg 2018, 16. ATZ-Fachtagung N2 - Die urbane Mobilität ist im Wandel und insbesondere neue innovative Geschäftsmodelle werden einen wesentlichen Teil zur Lösung von künftigen Mobilitätsbedürfnissen beitragen. Die sogenannte „Shared Mobility“ gilt aktuell neben der Elektrifizierung des Antriebes und autonomem Fahrzeugtechnologien als einer der wichtigsten Trendthemen in der Automobilindustrie. Neue Mobilitätsdienstleistungen verlangen dabei verstärkt auch neue Fahrzeugkonzepte. Y1 - 2018 U6 - https://doi.org/10.1007/978-3-658-22038-9_13 SP - 189 EP - 199 PB - Springer Vieweg CY - Wiesbaden ER - TY - CHAP A1 - Schartner, Karl-Heinz A1 - Loeb, H. W. A1 - Dachwald, Bernd A1 - Ohndorf, Andreas T1 - Perspectives of electric propulsion for outer planetary and deep space missions T2 - European Planetary Science Congress 2009 N2 - Solar-electric propulsion (SEP) is superior with respect to payload capacity, flight time and flexible launch window to the conventional interplanetary transfer method using chemical propulsion combined with gravity assists. This fact results from the large exhaust velocities of electric low–thrust propulsion and is favourable also for missions to the giant planets, Kuiper-belt objects and even for a heliopause probe (IHP) as shown in three studies by the authors funded by DLR. They dealt with a lander for Europa and a sample return mission from a mainbelt asteroid [1], with the TANDEM mission [2]; the third recent one investigates electric propulsion for the transfer to the edge of the solar system. All studies are based on triple-junction solar arrays, on rf-ion thrusters of the qualified RIT-22 type and they use the intelligent trajectory optimization program InTrance [3]. Y1 - 2009 N1 - European Planetary Science Congress 2009, 13-18 September, Potsdam, Germany SP - 416 EP - 416 ER - TY - JOUR A1 - Blome, Hans-Joachim A1 - Kosbow, Michael T1 - Perturbation of a satellite orbit by gravitational waves JF - Jahrbuch 2004 der Deutschen Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR) Y1 - 2004 SN - 0070-4083 N1 - DGLR-2004-168 SP - 2083 EP - 2088 PB - DGLR CY - Bonn ER - TY - CHAP A1 - Czupalla, Markus T1 - Pflanzen oder Maschinen - was läßt uns auf dem Mars überleben? T2 - Überleben im Weltraum. Auf dem Weg zu neuen Grenzen. 21. Berliner Kolloquium der Daimler und Benz Stiftung 24. Mai 2017 Y1 - 2017 SP - 12 EP - 12 ER - TY - JOUR A1 - Götten, Falk A1 - Finger, Felix T1 - PhoenAIX – Die modulare Transportdrohne JF - Ingenieurspiegel N2 - Die autonome, unbemannte Luftfahrt ist einer der Schlüsselsektoren für die Zukunft der Luftfahrt. In diesem rasant wachsenden Bereich nehmen senkrecht startende und senkrecht landende Flugzeuge (Vertical Take-Off and Landing – VTOL) einen besonderen Platz ein. Ein VTOL-Flugzeug (manchmal auch „Transitionsfluggerät“ genannt) verbindet die Eigenschaft des Helikopters, überall starten und landen zu können, mit den Geschwindigkeits-, Reichweiten und Flugdauervorteilen des Starrflüglers. Grundsätzlich wird die Senkrechtstart- und -landefähigkeit sowohl von zivilen als auch von militärischen Betreibern unbemannter Fluggeräte (UAVs) gewünscht. Trotzdem bietet der Markt nur eine geringe Anzahl von VTOL-UAVs, da qualitativ hochwertige Entwürfe eine ausgesprochene Herausforderung in der Entwicklung darstellen. An der FH Aachen wird deshalb seit über 5 Jahren an der Auslegung und Analyse von solchen unbemannten VTOL Flugzeugen geforscht. Das neuste Projekt ist der Eigenentwurf einer großen, senkrechtstartenden Transportdrohne. Das „PhoenAIX“ getaufte Fluggerät wird von Falk Götten und Felix Finger im Rahmen einer EFRE-Förderung entwickelt. Y1 - 2020 SN - 1868-5919 N1 - Project: UAV Design VL - 2020 IS - 1 SP - 38 EP - 40 PB - Public Verlag CY - Bingen ER - TY - JOUR A1 - Heiligers, Jeannette A1 - Schoutetens, Frederic A1 - Dachwald, Bernd T1 - Photon-sail equilibria in the alpha centauri system JF - Journal of Guidance, Control, and Dynamics Y1 - 2021 U6 - https://doi.org/10.2514/1.G005446 SN - 1533-3884 SN - 0731-5090 SN - 0162-3192 VL - 44 IS - 5 SP - 1053 EP - 1061 ER - TY - JOUR A1 - Gerhardt, Hans Joachim T1 - Physikalische Modelle für Brandsicherheitsnachweise = physical models for fire safety design JF - Kurzreferate : Hannover, 6. und 7. Juni 2005 = Proceedings / [Veranst.: VFDB, Vereinigung zur Förderung des Deutschen Brandschutzes e.V.; iBMB, Institut für Baustoffe, Massivbau und Brandschutz der Technischen Universität Braunschweig]. Hrsg.: Dietmar Hosser Y1 - 2005 SN - 3-89288-165-0 N1 - Internationales Brandschutz-Symposium <10, 2005, Hannover> SP - 135 EP - 154 PB - iBMB CY - Braunschweig ER - TY - JOUR A1 - Gerhardt, Hans Joachim T1 - Physikalische und brandschutztechnische Grundlagen des Rauch- und Wärmeabzugs JF - VDI-Berichte. 983 (1992) Y1 - 1992 SN - 0083-5560 N1 - Konferenz-Einzelbericht : Brandschutz im Industriebau. Regensburg, DE, 6.-7. Okt. 1992 SP - 51 EP - 69 ER - TY - JOUR A1 - Stadler, Alexander Maximilian A1 - Garvey, Christopher J. A1 - Embs, Jan Peter A1 - Koza, Michael Marek A1 - Unruh, Tobias A1 - Artmann, Gerhard A1 - Zaccai, Guiseppe T1 - Picosecond dynamics in haemoglobin from different species: A quasielastic neutron scattering study JF - Biochimica et biophysica acta (BBA): General Subjects Y1 - 2014 U6 - https://doi.org/10.1016/j.bbagen.2014.06.007 SN - 1872-8006 (E-Journal); 0304-4165 (Print) VL - 1840 IS - 10 SP - 2989 EP - 2999 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Kleine, Harald A1 - Kallweit, Stephan A1 - Michaux, Frank A1 - Havermann, Marc A1 - Olivier, Herbert T1 - PIV Measurement of Shock Wave Diffraction T2 - 18th International Symposium on Applications of Laser Techniques to Fluid Mechanics, 2016, Lissabon Y1 - 2016 SP - 1 EP - 14 ER - TY - JOUR A1 - Havermann, Marc A1 - Haertig, J. A1 - Rey, C. A1 - George, F. T1 - PIV measurements in Mach 3.5 and 4.5 shock tunnel flow / Haertig, J. ; Havermann, M. ; Rey, C. ; George, F. Y1 - 2001 N1 - AIAA-2001-699 Aerospace Sciences Meeting and Exhibit, 39th, Reno, NV, Jan. 8-11, 2001 PB - - ER - TY - BOOK A1 - Havermann, Marc T1 - PIV measurements in shock tunnels : PivNet 2, Final Workshop, Göttingen, 07. - 08.09.2006 Y1 - 2006 N1 - Publication / Institut Franco-Allemand de Recherches de Saint Louis ; 644 PB - ISL CY - Saint-Louis ER - TY - JOUR A1 - Havermann, Marc A1 - Haertig, J. A1 - Rey, C. A1 - George, A. T1 - PIV Measurements in Shock Tunnels and Shock Tubes / Havermann, M. ; Haertig, J. ; Rey, C. ; George, A. JF - Particle Image Velocimetry : New Developments and Recent Applications Y1 - 2008 SN - 978-3-540-73528-1 N1 - Topics in applied physics. Vol 112. SP - 429 EP - 442 PB - Springer CY - Berlin ER - TY - BOOK A1 - Havermann, Marc T1 - PIV measurements of compressible vortex rings generated by a shock tube : 13th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, PT, 26-29.06.2006; axe de recherches 2.14 / Haertig, J.; Rey, C.; Havermann, M. Institut Franco-Allemand de Recherches de Saint-Louis Y1 - 2006 N1 - Publication / Institut Franco-Allemand de Recherches de Saint Louis ; 645 PB - ISL CY - Saint-Louis ER - TY - BOOK A1 - Havermann, Marc T1 - PIV-Messungen im hohen Überschall am ISL-Stoßrohr-Windkanal : 11. Fachtagung Lasermethoden in der Strömungsmesstechnik, PTB Braunschweig, 9. - 11. September 2003 / Institut Franco-Allemand de Recherches de Saint-Louis. Havermann, M. ... Y1 - 2003 N1 - Publication / Institut Franco-Allemand de Recherches de Saint-Louis ; 655 PB - ISL CY - Saint-Louis ER - TY - JOUR A1 - Havermann, Marc A1 - Seiler, F. A1 - George, A. A1 - Leopold, F. T1 - Planar Velocity Visualization in High-Speed Wedge Flow using Doppler Picture Velocimetry (DPV) compared with Particle Image Velocimetry (PIV) / Seiler, F. ; Havermann, M. ; George, A. ; Leopold, F. ; Srulijes, J. JF - Journal of Visualization. 6 (2003), H. 3 Y1 - 2003 SN - 1343-8875 SP - 253 EP - 262 PB - - ER - TY - JOUR A1 - Dachwald, Bernd A1 - Baturkin, Volodymyr A1 - Coverstone, Victoria L. A1 - Dietrich, Benjamin A1 - Garbe, Gregory P. A1 - Görlich, Marianne A1 - Leipold, Manfred A1 - Lura, Franz A1 - Macdonald, Malcolm A1 - McInnes, Colin R. A1 - Mengali, Giovanni A1 - Quatra, Alessandro A. A1 - Rios-Reyes, Leonel A1 - Scheeres, Daniel J. A1 - Seboldt, Wolfgang A1 - Wie, Bong T1 - Potential Effects of Optical Solar Sail Degradation on Interplanetary Trajectory Design JF - Astrodynamics 2005 : proceedings of the AAS/AIAA astrodynamics conference held August 7 - 11, 2005, South Lake Tahoe, California / ed. by Bobby G. Williams. - Pt. 3. - (Advances in the astronautical sciences ; 123,3) Y1 - 2006 UR - http://www.spacesailing.net/paper/200508_LakeTahoe_Dachwald+.pdf SN - 0-87703-527-X N1 - Astrodynamics Conference <2005, South Lake Tahoe, Calif.> ; American Astronautical Society ; Number: AAS-05-413 SP - 2569 EP - 2592 PB - Univelt CY - San Diego, Calif. ER - TY - CHAP A1 - Dachwald, Bernd A1 - Baturkin, Volodymyr A1 - Coverstone, Victoria A1 - Diedrich, Ben A1 - Garbe, Gregory A1 - Görlich, Marianne A1 - Leipold, Manfred A1 - Lura, Franz A1 - Macdonald, Malcolm A1 - McInnes, Colin A1 - Mengali, Giovanni A1 - Quarta, Alessandro A1 - Rios-Reyes, Leonel A1 - Scheeres, Daniel J. A1 - Seboldt, Wolfgang A1 - Wie, Bong T1 - Potential effects of optical solar sail degredation on trajectory design T2 - AAS/AIAA Astrodynamics Specialist N2 - The optical properties of the thin metalized polymer films that are projected for solar sails are assumed to be affected by the erosive effects of the space environment. Their degradation behavior in the real space environment, however, is to a considerable degree indefinite, because initial ground test results are controversial and relevant inspace tests have not been made so far. The standard optical solar sail models that are currently used for trajectory design do not take optical degradation into account, hence its potential effects on trajectory design have not been investigated so far. Nevertheless, optical degradation is important for high-fidelity solar sail mission design, because it decreases both the magnitude of the solar radiation pressure force acting on the sail and also the sail control authority. Therefore, we propose a simple parametric optical solar sail degradation model that describes the variation of the sail film’s optical coefficients with time, depending on the sail film’s environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails. Using our model, the effects of different optical degradation behaviors on trajectory design are investigated for various exemplary missions. Y1 - 2005 N1 - 2005 AAS/AIAA Astrodynamics Specialist Conference, 7-11.08.2005. Lake Tahoe, California https://www.space-flight.org/AAS_meetings/2005_astro/2005_astro.html SP - 1 EP - 23 ER - TY - CHAP A1 - Thoma, Andreas A1 - Stiemer, Luc A1 - Braun, Carsten A1 - Fisher, Alex A1 - Gardi, Alessandro G. T1 - Potential of hybrid neural network local path planner for small UAV in urban environments T2 - AIAA SCITECH 2023 Forum N2 - This work proposes a hybrid algorithm combining an Artificial Neural Network (ANN) with a conventional local path planner to navigate UAVs efficiently in various unknown urban environments. The proposed method of a Hybrid Artificial Neural Network Avoidance System is called HANNAS. The ANN analyses a video stream and classifies the current environment. This information about the current Environment is used to set several control parameters of a conventional local path planner, the 3DVFH*. The local path planner then plans the path toward a specific goal point based on distance data from a depth camera. We trained and tested a state-of-the-art image segmentation algorithm, PP-LiteSeg. The proposed HANNAS method reaches a failure probability of 17%, which is less than half the failure probability of the baseline and around half the failure probability of an improved, bio-inspired version of the 3DVFH*. The proposed HANNAS method does not show any disadvantages regarding flight time or flight distance. Y1 - 2023 U6 - https://doi.org/10.2514/6.2023-2359 N1 - AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, Md & Online PB - AIAA CY - Reston, Va. ER - TY - JOUR A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang A1 - Macdonald, Malcolm A1 - Mengali, Giovanni A1 - Quatra, Alessandro A. A1 - McInnes, Colin R. A1 - Rios-Reyes, Leonel A1 - Scheerers, Daniel J. A1 - Wie, Bong A1 - Görlich, Marianne A1 - Lura, Franz A1 - Diedrich, Benjamin A1 - Baturkin, Volodymyr A1 - Coverstone, Victoria L. A1 - Leipold, Manfred A1 - Garbe, Gregory P. T1 - Potential Solar Sail Degradation Effects on Trajectory and Attitude Control JF - AIAA Guidance, Navigation and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : [San Francisco, California, 15 - 18 August 2005 ; papers]. - (AIAA meeting papers on disc ; [10.]2005,16-17) Y1 - 2005 SN - 1-56347-765-3 N1 - American Institute of Aeronautics and Astronautics ; AIAA Guidance, Navigation, and Control Conference and Exhibit <2005, San Francisco, Calif.> ; AIAA paper number: AIAA-2006-6172 Link "https://arc.aiaa.org/doi/book/10.2514/MGNC05" am 15.07.2022 nachgetragen Behr PB - American Institute of Aeronautics and Astronautics CY - Reston, Va. ER - TY - JOUR A1 - Funke, Harald A1 - Esch, Thomas A1 - Roosen, Petra T1 - Powertrain Adaptions for LPG Usage in General Aviation JF - MTZ worldwide N2 - In general aviation, too, it is desirable to be able to operate existing internal combustion engines with fuels that produce less CO₂ than Avgas 100LL being widely used today It can be assumed that, in comparison, the fuels CNG, LPG or LNG, which are gaseous under normal conditions, produce significantly lower emissions. Necessary propulsion system adaptations were investigated as part of a research project at Aachen University of Applied Sciences. Y1 - 2022 U6 - https://doi.org/10.1007/s38313-021-0756-6 VL - 2022 IS - 83 SP - 58 EP - 62 PB - Springer Nature CY - Basel ER - TY - GEN A1 - Hille, Sebastian A1 - Stumpf, Eike A1 - Mayntz, Joscha A1 - Dahmann, Peter T1 - Prediction of sound exposure caused by a landing motor glider with recuperating propellers T2 - AIAA SCITECH 2023 Forum N2 - This paper presents an approach to predicting the sound exposure on the ground caused by a landing aircraft with recuperating propellers. The noise source along the trajectory of a flight specified for a steeper approach is simulated based on measurements of sound power levels and additional parameters of a single propeller placed in a wind tunnel. To validate the measured data/measurement results, these simulations are also supported by overflight measurements of a test aircraft. It is shown that the simple source models of propellers do not provide fully satisfactory results since the sound levels are estimated too low. Nevertheless, with a further reference comparison, margins for an acceptable increase in the sound power level of the aircraft on its now steeper approach path could be estimated. Thus, in this case, a +7 dB increase in SWL would not increase the SEL compared to the conventional approach within only 2 km ahead of the airfield. Y1 - 2023 U6 - https://doi.org/10.2514/6.2023-0211 N1 - AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, Md & Online PB - AIAA CY - Reston, Va. ER - TY - CHAP A1 - Braun, Carsten A1 - Boucke, Alexander A1 - Hanke, M. A1 - Karavas, Alexandros A1 - Ballmann, Josef T1 - Prediction of the model deformation of a high speed transport aircraft type wing by direct aeroelastic simulation T2 - High performance computing in science and engineering '03. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2003 / Eds.: Egon Krause ... Y1 - 2003 SN - 978-3-540-40850-5 SP - 331 EP - 342 PB - Springer CY - Berlin ER - TY - JOUR A1 - Kezerashvili, Roman Ya A1 - Dachwald, Bernd T1 - Preface: Solar sailing: Concepts, technology, and missions II JF - Advances in Space Research Y1 - 2021 U6 - https://doi.org/10.1016/j.asr.2021.01.037 SN - 0273-1177 VL - 67 IS - 9 SP - 2559 EP - 2560 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Peloni, A. A1 - Ceriotti, M. A1 - Dachwald, Bernd T1 - Preliminary trajectory design of a multiple NEO rendezvous mission through solar sailing T2 - Proceedings of the International Astronautical Congress, IAC, Vol. 8, 2014 Y1 - 2015 SN - 978-1-63439-986-9 SP - 5352 EP - 5366 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Peeken, Heinz A1 - Troeder, Christoph A1 - Schmidt, J. A1 - Rosenkranz, Josef T1 - Principles of machine noise reduction T2 - Inter-noise 85 : proceedings ; 1985 international conference on noise control engineering ; Munich, Sept. 18 - 20, 1985. - (Schriftenreihe der Bundesanstalt für Arbeitsschutz : Tagungsbericht ; 39) Y1 - 1985 SN - 3-88314-417-7 SP - 23 EP - 36 PB - Bundesanstalt für Arbeitsschutz [u.a.] CY - Dortmund [u.a.] ER - TY - JOUR A1 - Thoma, Andreas A1 - Thomessen, Karolin A1 - Gardi, Alessandro A1 - Fisher, A. A1 - Braun, Carsten T1 - Prioritising paths: An improved cost function for local path planning for UAV in medical applications JF - The Aeronautical Journal N2 - Even the shortest flight through unknown, cluttered environments requires reliable local path planning algorithms to avoid unforeseen obstacles. The algorithm must evaluate alternative flight paths and identify the best path if an obstacle blocks its way. Commonly, weighted sums are used here. This work shows that weighted Chebyshev distances and factorial achievement scalarising functions are suitable alternatives to weighted sums if combined with the 3DVFH* local path planning algorithm. Both methods considerably reduce the failure probability of simulated flights in various environments. The standard 3DVFH* uses a weighted sum and has a failure probability of 50% in the test environments. A factorial achievement scalarising function, which minimises the worst combination of two out of four objective functions, reaches a failure probability of 26%; A weighted Chebyshev distance, which optimises the worst objective, has a failure probability of 30%. These results show promise for further enhancements and to support broader applicability. KW - Path planning KW - Cost function KW - Multi-objective optimization Y1 - 2023 U6 - https://doi.org/10.1017/aer.2023.68 SN - 0001-9240 (Print) SN - 2059-6464 (Online) IS - First View SP - 1 EP - 18 PB - Cambridge University Press CY - Cambridge ER - TY - CHAP A1 - Knobloch, V. A1 - Kowalski, Julia A1 - Bösiger, P. A1 - Kozerke, S. T1 - Probabilistic Streamline Estimation from Accelerated Fourier Velocity Encoded Measurements T2 - Proceedings of the 19th ISMRM International Society for Magnetic Resonance in Medicine Y1 - 2011 N1 - ISMRM 19th Annual Meeting & Exhibition in Montréal, Québec, Canada SP - 1215 EP - 1215 ER - TY - CHAP A1 - Heimes, Heiner Hans A1 - Kampker, Achim A1 - Dorn, Benjamin A1 - Kehrer, Mario A1 - Dünnwald, Simon A1 - Badura, Dennis A1 - Terren, Maximilian A1 - Röth, Thilo ED - Kampker, Achim ED - Heimes, Heiner Hans T1 - Produktionsprozesse der Fahrzeugstruktur T2 - Elektromobilität: Grundlagen einer Fortschrittstechnologie Y1 - 2023 SN - 978-3-662-65811-6 (Print) SN - 978-3-662-65812-3 (Online) U6 - https://doi.org/10.1007/978-3-662-65812-3_13 N1 - Corresponding author: Benjamin Dorn SP - 227 EP - 247 PB - Springer Vieweg CY - Berlin ER - TY - JOUR A1 - Havermann, Marc A1 - Seiler, F. A1 - Georges, A. A1 - Srulijes, J. T1 - Progress in Doppler picture velocimetry (DPV) / Seiler, F. ; George, A. ; Srulijes, J. ; Havermann, M. JF - Experiments in Fluids. 44 (2008), H. 3 Y1 - 2008 SN - 1432-1114 SP - 389 EP - 395 PB - - ER - TY - BOOK A1 - Havermann, Marc A1 - Seiler, F. A1 - George, A. A1 - Srulijes, J. T1 - Progress in doppler picture velocimetry (DPV) technique : 12th International Symposium on Flow Visualization, DLR, Göttingen, September 10 - 14, 2006 / Institut Franco-Allemand de Recherches de Saint-Louis. Seiler, F. ... Y1 - 2006 N1 - Publication / Institut Franco-Allemand de Recherches de Saint Louis ; 624 PB - ISL CY - Saint-Louis ER - TY - CHAP A1 - Seboldt, Wolfgang A1 - Blome, Hans-Joachim A1 - Dachwald, Bernd A1 - Richter, Lutz T1 - Proposal for an integrated European space exploration strategy T2 - 55th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law N2 - Recently, in his vision for space exploration, US president Bush announced to extend human presence across the solar system, starting with a human return to the Moon as early as 2015 in preparation for human exploration of Mars and other destinations. In Europe, an exploration program, termed AURORA, was established by ESA in 2001 – funded on a voluntary basis by ESA member states – with a clear focus on Mars and the ultimate goal of landing humans on Mars around 2030 in international cooperation. In 2003, a Human Spaceflight Vision Group was appointed by ESA with the task to develop a vision for the role of human spaceflight during the next quarter of the century. The resulting vision focused on a European-led lunar exploration initiative as part of a multi-decade, international effort to strengthen European identity and economy. After a review of the situation in Europe concerning space exploration, the paper outlines an approach for a consistent positioning of exploration within the existing European space programs, identifies destinations, and develops corresponding scenarios for an integrated strategy, starting with robotic missions to the Moon, Mars, and near-Earth asteroids. The interests of the European planetary in-situ science community, which recently met at DLR Cologne, are considered. Potential robotic lunar missions comprise polar landings to search for frozen volatiles and a sample return. For Mars, the implementation of a modest robotic landing mission in 2009 to demonstrate the capability for landing and prepare more ambitious and complex missions is discussed. For near-Earth asteroid exploration, a low-cost in-situ technology demonstration mission could yield important results. All proposed scenarios offer excellent science and could therefore create synergies between ESA’s mandatory and optional programs in the area of planetary science and exploration. The paper intents to stimulate the European discussion on space exploration and reflects the personal view of the authors. Y1 - 2004 N1 - 55th International Astronautical Congress 2004 - Vancouver, Canada SP - 1 EP - 10 ER -