TY  - CHAP
A1  - Funke, Harald
A1  - Börner, Sebastian
A1  - Keinz, Jan
A1  - Hendrick, P.
A1  - Recker, E.
T1  - Low NOx Hydrogen combustion chamber for industrial gas turbine applications“, 14th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery
T2  - ISROMAC-14 : the Forteenth International Symposium on Transport Phenomena and Dynamics of Rotating Machinery ; Honolulu, Hawaii, February 27 - March 02nd, 2012
Y1  - 2012
N1  - International Symposium on Transport Phenomena and Dynamics of Rotating Machinery ; (14 ; 2012.02.27-03.02 ; Honolulu, Hawaii)
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Carnelli, I.
A1  - Vasile, M.
T1  - Low-Thrust Gravity Assist Trajectory Optimization Using Evolutionary Neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile ...
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
SN  - 0-87703-527-X
N1  - Astrodynamics Conference <2005, South Lake Tahoe, Calif.> ; American Astronautical Society ; Number: AAS-05-374
SP  - 1911
EP  - 1928
PB  - Univelt
CY  - San Diego, Calif.
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
T1  - Low-Thrust Mission Analysis and Global Trajectory Optimization Using Evolutionary Neurocontrol: New Results
T2  - European Workshop on Space Mission Analysis ESA/ESOC, Darmstadt, Germany 10 { 12 Dec 2007
N2  - Interplanetary trajectories for low-thrust spacecraft are often characterized by multiple revolutions around the sun. Unfortunately, the convergence of traditional trajectory optimizers that are based on numerical optimal control methods depends strongly on an adequate initial guess for the control function (if a direct method is used) or for the starting values of the adjoint vector (if an indirect method is used). Especially when many revolutions around the sun are re-
quired, trajectory optimization becomes a very difficult and time-consuming task that involves a lot of experience and expert knowledge in astrodynamics and optimal control theory, because an adequate initial guess is extremely hard to find. Evolutionary neurocontrol (ENC) was proposed as a smart method for low-thrust trajectory optimization that fuses artificial neural networks and evolutionary algorithms to so-called evolutionary neurocontrollers (ENCs) [1]. Inspired by natural archetypes, ENC attacks the trajectoryoptimization problem from the perspective of artificial intelligence and machine learning, a perspective that is quite different from that of optimal control theory. Within the context of ENC, a trajectory is regarded as the result of a spacecraft steering strategy that maps permanently the actual spacecraft state and the actual target state onto the actual spacecraft control vector. This way, the problem of searching the optimal spacecraft trajectory is equivalent to the problem of searching (or "learning") the optimal spacecraft steering strategy. An artificial neural network is used to implement such a spacecraft steering strategy. It can be regarded as a parameterized function (the network function) that is defined by the internal network parameters. Therefore, each distinct set of network parameters defines a different network function and thus a different steering strategy. The problem of searching the optimal steering strategy is now equivalent to the problem of searching the optimal set of network parameters. Evolutionary algorithms that work on a population of (artificial) chromosomes are used to find the optimal network parameters, because the parameters can be easily mapped onto a chromosome. The trajectory optimization problem is solved when the optimal chromosome is found. A comparison of solar sail trajectories that have been published by others [2, 3, 4, 5] with ENC-trajectories has shown that ENCs can be successfully applied for near-globally optimal spacecraft control [1, 6] and that they are able to find trajectories that are closer to the (unknown) global optimum, because they explore the trajectory search space more exhaustively than a human expert can do. The obtained trajectories are fairly accurate with respect to the terminal constraint. If a more accurate trajectory is required, the ENC-solution can be used as an initial guess for a local trajectory optimization method. Using ENC, low-thrust trajectories can be optimized without an initial guess and without expert attendance.
Here, new results for nuclear electric spacecraft and for solar sail spacecraft are presented and it will be shown that ENCs find very good trajectories even for very difficult problems. Trajectory optimization results are presented for 1. NASA's Solar Polar Imager Mission, a mission to attain a highly inclined close solar orbit with a solar sail [7] 2. a mission to de ect asteroid Apophis with a solar sail from a retrograde orbit with a very-high velocity impact [8, 9] 3. JPL's \2nd Global Trajectory Optimization Competition", a grand tour to visit four asteroids from different classes with a NEP spacecraft
Y1  - 2007
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  - Mertens, Josef
T1  - Luft hat keine Balken, aber enorme Kräfte : Aerodynamik - die unsichtbare Kraft
JF  - HEmagazin : das Hocheffizienz-Magazin von Wilo. 2006 (2006), H. 1
Y1  - 2006
SP  - 4
EP  - 9
PB  - -
ER  - 
TY  - JOUR
A1  - Esch, Thomas
A1  - Pischinger, M.
A1  - Göbel, T.
T1  - Luft- und Kraftstoffzumessung bei Ottomotoren mit variabler Ventilsteuerung
JF  - Motortechnische Zeitschrift. 57 (1996), H. 2
Y1  - 1996
SN  - 0024-8525
SP  - 106
EP  - 115
ER  - 
TY  - JOUR
A1  - Gerhardt, Hans Joachim
T1  - Lufttechnische Prüfungen von Abzügen - Kritische Anmerkungen zur Prüfvorschrift DIN 12 924 Teil 1
JF  - GIT Spezial: Arbeitschutz (1994)
Y1  - 1994
SN  - 0940-032X
SP  - 90
EP  - 95
ER  - 
TY  - JOUR
A1  - Gerhardt, Hans Joachim
T1  - Lösungskonzept zur Belüftung von Rottehallen
JF  - Abfallwirtschaftsjournal. 6 (1994), H. 10
Y1  - 1994
SN  - 0934-6422
SP  - 689
EP  - 692
ER  - 
TY  - JOUR
A1  - Fornaciari, Andrea
A1  - Guidetti, Marco
A1  - Havermann, Marc
A1  - Lettini, Antonio
T1  - Maccine mobili più efficienti
JF  - Fluidotecnica
N2  - Secondo le attuali normative tutte le macchine mobili, entro il 2012, dovranno essere soggette a un incremento di efficienza energetica. Un’evoluzione del sistema idraulico potrà contribuire in maniera significativa al miglioramento richiesto. Elettronica e idraulica sempre più protagoniste.
Y1  - 2010
IS  - 345
SP  - 11
EP  - 14
PB  - Quine Business Publisher
CY  - Milano
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
A1  - Loeb, H. W.
A1  - Schartner, Karl-Heinz
T1  - Main Belt Asteroid Sample Return Mission Using Solar Electric Propulsion
JF  - Acta Astronautica. 63 (2008), H. 1-4
Y1  - 2008
SN  - 0094-5765
N1  - International Astronautical Federation Congress <58, 2007, Hyderabad> ; International Astronautical Congress <58, 2007, Hyderabad> ; IAC-07-A3.5.07
SP  - 91
EP  - 101
ER  -