TY - CHAP A1 - Dachwald, Bernd T1 - Global optimization of low-thrust space missions using evolutionary neurocontrol T2 - Proceedings of the international workshop on global optimization N2 - Low-thrust space propulsion systems enable flexible high-energy deep space missions, but the design and optimization of the interplanetary transfer trajectory is usually difficult. It involves much experience and expert knowledge because the convergence behavior of traditional local trajectory optimization methods depends strongly on an adequate initial guess. Within this extended abstract, evolutionary neurocontrol, a method that fuses artificial neural networks and evolutionary algorithms, is proposed as a smart global method for low-thrust trajectory optimization. It does not require an initial guess. The implementation of evolutionary neurocontrol is detailed and its performance is shown for an exemplary mission. KW - Evolutionary Neurocontrol KW - Spacecraft Trajectory Optimization KW - Low-Thrust Propulsion Y1 - 2005 SP - 85 EP - 90 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 - 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 - Mathiak, Gerhard A1 - Willnecker, Rainer A1 - Plescher, Engelbert T1 - Vibrational effects on diffusion experiments JF - Microgravity science and technology : international journal for microgravity research and applications Y1 - 2005 SN - 0938-0108 VL - Vol. 15 IS - No. 1 SP - 295 EP - 300 ER - TY - JOUR A1 - Mathiak, Gerhard A1 - Plescher, Engelbert A1 - Willnecker, Rainer T1 - Liquid metal diffusion experiments in microgravity - Vibrational effects JF - Measurement science and technology Y1 - 2005 U6 - http://dx.doi.org/10.1088/0957-0233/16/2/003 SN - 0957-0233 VL - Vol. 16 IS - No. 2 SP - 336 ER - TY - CHAP A1 - Plescher, Engelbert A1 - Mathiak, Gerhard A1 - Willnecker, Rainer T1 - Technical aspects of liquid diffusion model experiments T2 - 55th International Astronautical Congress : October 4 - 8, 2004, Vancouver, Canada / International Astronautical Federation. Bd. 8. IAC-04-J.5.04 Y1 - 2005 SP - 5019 EP - 5025 PB - International Astronautical Federation CY - Paris ER - TY - CHAP A1 - Braun, Carsten A1 - Boucke, Alexander A1 - Ballmann, Josef T1 - Numerical study of the influence of dynamic pressure and deflected ailerons on the deformation of a high speed wing model T2 - High performance computing in science and engineering '04. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2004 / Eds.: Egon Krause ... Y1 - 2005 SN - 3-540-22943-4 SP - 225 EP - 236 PB - Springer CY - Berlin ER - TY - CHAP A1 - Braun, Carsten A1 - Boucke, Alexander A1 - Ballmann, Josef T1 - Numerical prediction of the wing deformation of a high speed transport aircraft type wind tunnel model by direct aeroelastic simulation T2 - Conference proceedings : CEAS/AIAA/DGLR International Forum on Aeroelasticity and Structural Dynamics IFASD 2005 : München, June 28 - July 1, 2005. DGLR-Bericht. 2005,04 Y1 - 2005 SN - 3-932182-43-X PB - DGLR CY - Bonn ER - TY - JOUR A1 - Havermann, Marc A1 - Kainuma, M. A1 - Takayama, K. T1 - Influence of Physical and Geometrical Parameters on Vortex Rings Generated by a Shock Tube / Havermann, M. ; Kainuma, M. ; Takayama, K. JF - Non-lethal options enhancing security and stability : 3rd European Symposium on Non-Lethal Weapons, May 10 - 12, 2005, Ettlingen, Germany / ICT, Fraunhofer-Institut Chemische Technologie; European Working Group Non-Lethal Weapons Y1 - 2005 N1 - European Symposium on Non-Lethal Weapons ; (3 ; 2005.5.10-12 ; Ettlingen); V 24 PB - ICT CY - Pfinztal ER - TY - JOUR A1 - Havermann, Marc A1 - Moeglin, J.-P. T1 - ISL's Research on Systems with Controlled Effects for Non-Lethal Applications / Moeglin, J.-P. ; Havermann, M. et al. JF - Non-lethal options enhancing security and stability : 3rd European Symposium on Non-Lethal Weapons, May 10 - 12, 2005, Ettlingen, Germany / ICT, Fraunhofer-Institut Chemische Technologie; European Working Group Non-Lethal Weapons Y1 - 2005 N1 - European Symposium on Non-Lethal Weapons ; (3 ; 2005.5.10-12 ; Ettlingen); P 35 PB - ICT CY - Pfinztal ER - TY - BOOK A1 - Havermann, Marc T1 - Development of a free flight force measuring (FFM) technique at the ISL shock tube laboratory : 25th International Symposium on Shock Waves, ISSW25, Bangalore, India, July 17 - 22, 2005 / Institut Franco-Allemand de Recherches de Saint-Louis. Seiler, F. ; Mathieu, G. ; George, A. ; Srulijes, J. ; Sauerwein, B. ; Havermann, M. Y1 - 2005 N1 - Publication / Institut Franco-Allemand de Recherches de Saint-Louis ; 620 PB - ISL CY - Saint-Louis ER - TY - JOUR A1 - Havermann, Marc A1 - Ende, H. A1 - Seiler, F. A1 - Schwenzer, M. T1 - Shock tunnel measurement of the interaction amplification factor for a hot gas side jet in a supersonic cross flow / Havermann, M. ; Ende, H. ; Seiler, F. ; Schwenzer, M. JF - Shock Waves : Proceedings of the 24th International Symposium on Shock Waves Beijing, China July 11-16, 2004 / edited by Z. Jiang Y1 - 2005 SN - 978-3-540-22497-6 SP - 113 EP - 118 PB - Springer CY - Berlin ER - TY - JOUR A1 - Havermann, Marc T1 - Effects of the shock tube open-end shape on vortex loops released from it / Kainuma, M. ; Havermann, M. ; Sun, M. ; Takayama, K. JF - Shock Waves : Proceedings of the 24th International Symposium on Shock Waves Beijing, China July 11-16, 2004 / edited by Z. Jiang Y1 - 2005 SN - 978-3-540-22497-6 SP - 505 EP - 510 PB - Springer CY - Berlin ER - TY - JOUR A1 - Havermann, Marc A1 - Seiler, F. A1 - Boller, F. A1 - Mangold, P. T1 - Operation of the ISL transonic shock tube in a high subsonic flow regime / Seiler, F. ; Havermann, M. ; Boller, F. ; Mangold, P. ; Takayama K. JF - Shock Waves : Proceedings of the 24th International Symposium on Shock Waves Beijing, China July 11-16, 2004 / edited by Z. Jiang Y1 - 2005 SN - 978-3-540-22497-6 SP - 307 EP - 312 PB - Springer CY - Berlin 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 - Design methods of smoke and heat exhaust systems in construction works JF - V Mie̜dzynarodowa Konferencja Bezpieczeństwo Pożarowe Budowli, Warszawa-Miedzeszyn, 14 - 16 listopada 2005 r. = : Vth International Conference Fire Safety of Buildings / ITB ... [Ed. Mirosław Kosiorek] Y1 - 2005 SN - 83-7413-810-6 N1 - Mie̜dzynarodowa Konferencja Bezpieczeństwo Pożarowe Budowli <5, 2005, Warszawa> ; International Conference Fire Safety of Buildings <5, 2005, Warszawa-Miedzeszyn> SP - 127 EP - 140 PB - ITB CY - Warszawa ER - TY - JOUR A1 - Gerhardt, Hans Joachim A1 - Schönwald, J. A1 - Forßmann, R. A1 - Große, Wolfgang T1 - Modulation der Windenergie durch optimierte Uferbepflanzung zur Steuerung der Oberflächenströmung für das Entfernung von Treibgut JF - Der Fühlinger See : Beiträge zur Erhaltung der ökologischen Qualität / hrsg. von Wolfgang Große ... - (Ökologie und nachhaltige Entwicklung von Sport- und Freizeitseen ; 1) Y1 - 2005 SN - 3-86582-212-6 SP - 95 EP - 108 PB - Monsenstein und Vannerdat CY - Münster ER - TY - JOUR A1 - Gerhardt, Hans Joachim A1 - Konrath, B. A1 - Lieb, R.-D. T1 - Das Drallrohr JF - HLH : Lüftung, Klima, Heizung, Sanitär, Gebäudetechnik. 56 (2005), H. 11 Y1 - 2005 SN - 1436-5103 N1 - 2. ISSN: 0017-9906 ; 3. ISSN: 1434-422X ; Zeitschrift unter 13 Z 739 in der Bibliothek SP - 91 EP - 95 ER - TY - JOUR A1 - Gerhardt, Hans Joachim T1 - Teures Bauen durch starre Genehmigungspraxis JF - Der Bausachverständige : Zeitschrift für Bauschäden, Grundstückswert und gutachterliche Tätigkeit. 1 (2005), H. 5 Y1 - 2005 SN - 1614-6123 SP - 44 EP - 45 ER - TY - JOUR A1 - Gerhardt, Hans Joachim A1 - Lieb, R.-D. T1 - Entrauchung komplexer Räumlichkeiten : Strategien und Steuerungen JF - Tür-Tor-Fenster-Report : Fachzeitschrift für die Technologien von Türen, Toren und Fenstern. 25 (2005), H. 3 Y1 - 2005 SN - 0724-7702 SP - 27 EP - 29 ER -