TY  - CHAP
A1  - Wu, Ziyi
A1  - Kemper, Hans
T1  - The optimal 48 V – battery pack for a specific load profile of a heavy duty vehicle
T2  - 8. Internationale Fachtagung Kraftwerk Batterie : 26. – 27. April 2016, Münster, Deutschland
Y1  - 2016
ER  - 
TY  - CHAP
A1  - Wolff, Nino
A1  - Seefeldt, Patric
A1  - Bauer, Wolfgang
A1  - Fiebig, Christopher
A1  - Gerding, Patrick
A1  - Parow-Souchon, Kai
A1  - Pongs, Anna
A1  - Reiffenrath, Matti
A1  - Ziemann, Thomas
T1  - Alternative application of solar sail technology
T2  - Advances in solar sailing
N2  - The development of Gossamer sail structures for solar sails contributes to a large field of future space applications like thin film solar generators, membrane antennas and drag sails. The focus of this paper is the development of a drag sail based on solar sail technology that could contribute to a reduction of space debris in low Earth orbits. The drag sail design and its connections to solar sail development, a first test on a sounding rocket, as well as the ongoing integration of the drag sail into a triple CubeSat is presented.
Y1  - 2014
SN  - 978-3-642-34906-5 (Print) ; 978-3-642-34907-2 (E-Book)
U6  - http://dx.doi.org/10.1007/978-3-642-34907-2_23
SP  - 351
EP  - 365
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Ulamec, S.
A1  - Feuerbacher, B.
A1  - Rosenbauer, H. (u.a.)
T1  - Rosetta Lander - In Situ Investigation of a Cometary Nucleus
JF  - Lunar and Planetary Science. 28 (1997)
Y1  - 1997
SN  - 0270-9511
N1  - Proceedings of the 28th Annual Lunar and Planetary Science Conference, March 17-21, 1997, Houston, Texas
SP  - 1461
EP  - 1462
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Ulamec, S.
A1  - Feuerbacher, B.
A1  - Rosenbauer, H.
T1  - Technical Challenge, Scientific Thrill: A Long Term Lander on an Active Comet
JF  - Lunar and Planetary Science. 26 (1995)
Y1  - 1995
SN  - 0270-9511
N1  - Proceedings of the 26th Lunar and Planetary Science Conference / org. by Lunar and Planetary Institute, Houston Texas
SP  - 1431
EP  - 1432
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Ulamec, S
A1  - Richter, L
T1  - Lander Systems for Planetary Missions
JF  - Laboratory astrophysics and space research / ed. by P. Ehrenfreund
Y1  - 1999
SN  - 0-7923-5338-2
N1  - Serie Astrophysics and space science library 236
SP  - 597
EP  - 621
PB  - Kluwer
CY  - Dordrecht [u.a.]
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Schmidt, H. P.
A1  - Padeken, D.
A1  - Hildmann, B.
T1  - The Microgravity User Support Centre (MUSC)
JF  - ESA SP. 277 (1988)
Y1  - 1988
SN  - 0379-6566
N1  - Proceedings of the International Symposium on Europe in Space--the Manned Space System : 25-29 April 1988, Strasbourg, France  David, Valerie ; Longdon, Norman [ed]
SP  - 525
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Schmidt, H. P.
A1  - Feuerbacher, B.
T1  - Microgravity research and user support in the Space Station era: The Microgravity User Support Centre
JF  - Acta Astronautica. 17 (1988), H. 11-12
Y1  - 1988
SN  - 0094-5765
SP  - 1161
EP  - 1168
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Padeken, D.
T1  - The User Center for Microgravity MUSC - Support for space experiments
JF  - DLR-Nachrichten. 70 (1993)
Y1  - 1993
SN  - 0937-0420
SP  - 19
EP  - 24
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Kell, G.
A1  - Winkler, F.
A1  - Günther, M. (u.a.)
T1  - High resolution temperature measurement technique for materials sciences experiments in space
JF  - Acta Astronautica. 43 (1998), H. 7-8
Y1  - 1998
SN  - 0094-5765
SP  - 385
EP  - 395
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Kehr, J.
A1  - Willnecker, R.
T1  - Decentralized Payload Operations Concept for Columbus
Y1  - 2000
N1  - 51st IAF Congress, Rio de Janeiro, Brazil, Oct. 2000
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Gillessen, F.
A1  - Otto, G.
A1  - Röstel, R.
T1  - Undercooling and solidification of metallic melts suspended in a non-nucleating matrix: Experiment NUCAL of the German Spacelab Mission D-2
JF  - Acta Astronautica. 38 (1996), H. 1
Y1  - 1996
SN  - 0094-5765
SP  - 63
EP  - 68
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Fortezza, R.
T1  - Telescience opportunities in the precursor flights
JF  - Space Technology - Industrial and Commercial Applications. 13 (1992), H. 2
Y1  - 1992
SN  - 0892-9270
SP  - 221
EP  - 226
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Feuerbacher, B.
A1  - Ulamec, S.
A1  - Rosenbauer, H. (u.a.)
T1  - Rosetta Lander - In Situ Characterisation of a Comet Nucleus
JF  - Acta Astronautica. 45 (1999), H. 4-9
Y1  - 1999
SN  - 0094-5765
SP  - 389
EP  - 395
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Bibring, J.-P.
A1  - Rosenbauer, H.
A1  - Boehnhardt, H.
T1  - The Rosetta Lander (“Philae”) Investigations  / Bibring, J.-P. ; Rosenbauer, H. ; Boehnhardt, H. ;  [...] Wittmann, K.
JF  - Space Science Reviews. 128 (2007), H. 1-4
Y1  - 2007
SN  - 0038-6308
SP  - 205
EP  - 220
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Bewersdorff, A.
A1  - Görler, G.P.
A1  - Otto, G.
T1  - Solidification of silver-germanium alloys in an amorphous matrix aboard the space station Mir
JF  - Acta Astronautica. 29 (1993), H. 7
Y1  - 1993
SN  - 0094-5765
SP  - 547
EP  - 552
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
T1  - The microgravity User Support Centre
JF  - Space Technology - Industrial and Commercial Applications. 13 (1993), H. 2
Y1  - 1993
SN  - 0892-9270
SP  - 121
EP  - 124
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  - JOUR
A1  - Wilson, Thomas L
A1  - Blome, Hans-Joachim
A1  - LaFave, Norman
T1  - Astrophysical Cosmology Using a Lunar Ligo
JF  - Engineering, construction, and operations in space V : proceedings of the Fifth International Conference on Space '96, Albuquerque, New Mexico, June 1-6, 1996 / sponsored by Aerospace Division of the American Society of Civil Engineers ... [et al.]; edite
Y1  - 1996
SN  - 0-7844-0177-2
SP  - 861
EP  - 863
PB  - The Society
CY  - New York
ER  - 
TY  - JOUR
A1  - Wilson, T. L.
A1  - Blome, Hans-Joachim
T1  - The Pioneer anomaly and a rotating Gödel universe
JF  - Advances in Space Research
Y1  - 2009
SN  - 0273-1177
VL  - 44
IS  - 11
SP  - 1345
EP  - 1353
ER  - 
TY  - JOUR
A1  - Wild, Dominik
A1  - Schrezenmeier, Johannes
A1  - Czupalla, Markus
A1  - Förstner, Markus
T1  - Thermal Characterization of additive manufactured Integral Structures for Phase Change Applications
JF  - 2020 International Conference on Environmental Systems
N2  - “Infused Thermal Solutions” (ITS) introduces a method for passive thermal control to stabilize structural components thermally without active heating and cooling systems, by using phase change material (PCM) in combination with lattice – both embedded into an additive manufactured integral structure. The technology is currently under development. This paper presents the results of the thermal property measurements performed on additive manufactured ITS breadboards. Within the breadboard campaigns key characteristics of the additive manufactured specimens were derived: Mechanical parameters: specimen impermeability, minimum wall thickness, lattice structure, subsequent heat treatment. Thermal properties: thermo-optical surface properties of the additive manufactured raw material, thermal conductivity and specific heat capacity measurements. As a conclusion the paper introduces an overview of potential ITS hardware applications, expected to increase the thermal performance.
Y1  - 2020
PB  - Texas Tech University
ER  - 
TY  - CHAP
A1  - Wellmer, Georg
A1  - Chen, B.-H.
A1  - Braun, Carsten
A1  - Ballmann, Josef
T1  - Numerical prediction of aeroelastic effects on twin-sting-rig mounted models for rear fuselage and empennage flow investigation in transonic windtunnel
T2  - Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics, June 18 - 21, 2007, Stockholm, Sweden
Y1  - 2007
PB  - KTH
CY  - Stockholm
ER  - 
TY  - CHAP
A1  - Weiss, Alexander
A1  - Abanteriba, Sylvester
A1  - Esch, Thomas
T1  - Investigation of Flow Separation Inside a Conical Rocket Nozzle With the Aid of an Annular Cross Flow
T2  - Proceedings of the ASME/JSME 2007 5th Joint Fluids Engineering Conference. Volume 1: Symposia, Parts A and B
N2  - Flow separation is a phenomenon that occurs in all kinds of supersonic nozzles sometimes during run-up and shut-down operations. Especially in expansion nozzles of rocket engines with large area ratio, flow separation can trigger strong side loads that can damage the structure of the nozzle. The investigation presented in this paper seeks to establish measures that may be applied to alter the point of flow separation. In order to achieve this, a supersonic nozzle was placed at the exit plane of the conical nozzle. This resulted in the generation of cross flow surrounding the core jet flow from the conical nozzle. Due to the entrainment of the gas stream from the conical nozzle the pressure in its exit plane was found to be lower than that of the ambient. A Cold gas instead of hot combustion gases was used as the working fluid. A mathematical simulation of the concept was validated by experiment. Measurements confirmed the simulation results that due to the introduction of a second nozzle the pressure in the separated region of the conical nozzle was significantly reduced. It was also established that the boundary layer separation inside the conical nozzle was delayed thus allowing an increased degree of overexpansion. The condition established by the pressure measurements was also demonstrated qualitatively using transparent nozzle configurations.
Y1  - 2007
SN  - 0-7918-4288-6
U6  - http://dx.doi.org/10.1115/FEDSM2007-37387
N1  - Proceedings of the ASME/JSME 2007 5th Joint Fluids Engineering Conference. Volume 1: Symposia, Parts A and B. San Diego, California, USA. July 30–August 2, 2007
SP  - 1861
EP  - 1871
PB  - American Society of Mechanical Engineers (ASME)
CY  - New York
ER  - 
TY  - CHAP
A1  - Weber, Tobias
A1  - Tellis, Jane J.
A1  - Duhovic, Miro
T1  - Characterization of tool-part-interaction an interlaminar friction for manufacturing process simulation
T2  - ECCM 17, 17th European Conference on Composite Materials, München, DE, Jun 26-30, 2016
Y1  - 2016
SN  - 978-3-00-053387-7
SP  - 1
EP  - 7
ER  - 
TY  - JOUR
A1  - Weber, Tobias
A1  - Ruff-Stahl, Hans-Joachim K.
T1  - Advances in Composite Manufacturing of Helicopter Parts
JF  - International Journal of Aviation, Aeronautics, and Aerospace
Y1  - 2017
U6  - http://dx.doi.org/10.15394/ijaaa.2017.1153
SN  - 2374-6793
VL  - 4
IS  - 1
ER  - 
TY  - CHAP
A1  - Weber, Tobias
A1  - Englhard, Markus
A1  - Hailer, Benjamin
A1  - Arent, Jan-Christoph
T1  - Manufacturing Process Simulation for the Prediction of Tool-Part-Interaction and Ply Wrinkling
T2  - Proceedings of SAMPE Europe Conference 2019, Nantes, France
Y1  - 2019
SP  - 1
EP  - 10
ER  - 
TY  - CHAP
A1  - Weber, Tobias
A1  - Englhard, Markus
A1  - Hailer, Benjamin
A1  - Arent, Jan-Christoph
T1  - Manufacturing Process Simulation for the Prediction of Tool-Part-Interaction and Ply Wrinkling
T2  - Proceedings of SAMPE Europe Conference, Amiens , France
Y1  - 2015
SP  - 1
EP  - 10
ER  - 
TY  - JOUR
A1  - Weber, Tobias
A1  - Englhard, Markus
A1  - Arent, Jan-Christoph
A1  - Hausmann, Joachim
T1  - An experimental characterization of wrinkling generated during prepreg autoclave manufacturing using caul plates
JF  - Journal of Composite Materials
Y1  - 2019
U6  - http://dx.doi.org/10.1177/0021998319846556
SN  - 1530-793X
VL  - 53
IS  - 26-27
SP  - 3757
EP  - 3773
ER  - 
TY  - JOUR
A1  - Weber, Tobias
A1  - Arent, Jan-Christoph
A1  - Steffen, Lucas
A1  - Balvers, Johannes M.
A1  - Duhovic, Miro
T1  - Thermal optimization of composite autoclave molds using the shift factor approach for boundary condition estimation
JF  - Journal of Composite Materials
Y1  - 2017
U6  - http://dx.doi.org/10.1177/0021998317699868
SN  - 1530-793X
VL  - 51
IS  - 12
SP  - 1753
EP  - 1767
PB  - Sage
CY  - London
ER  - 
TY  - JOUR
A1  - Weber, Tobias
A1  - Arent, Jan-Christoph
A1  - Münch, Lukas
A1  - Duhovic, Miro
A1  - Balvers, Johannes M.
T1  - A fast method for the generation of boundary conditions for thermal autoclave simulation
JF  - Composites Part A
N2  - Manufacturing process simulation enables the evaluation and improvement of autoclave mold concepts early in the design phase. To achieve a high part quality at low cycle times, the thermal behavior of the autoclave mold can be investigated by means of simulations. Most challenging for such a simulation is the generation of necessary boundary conditions. Heat-up and temperature distribution in an autoclave mold are governed by flow phenomena, tooling material and shape, position within the autoclave, and the chosen autoclave cycle. This paper identifies and summarizes the most important factors influencing mold heat-up and how they can be introduced into a thermal simulation. Thermal measurements are used to quantify the impact of the various parameters. Finally, the gained knowledge is applied to develop a semi-empirical approach for boundary condition estimation that enables a simple and fast thermal simulation of the autoclave curing process with reasonably high accuracy for tooling optimization.
Y1  - 2016
U6  - http://dx.doi.org/10.1016/j.compositesa.2016.05.036
SN  - 1359-835X
VL  - 88
SP  - 216
EP  - 225
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Weber, Tobias
T1  - Manufacturing Process Simulation for Tooling Optimization: Reduction of Quality Issues During Autoclave Manufacturing of Composite Parts
T2  - Proceedings of SAMPE Europe Conference 2015, Amiens, France
Y1  - 2015
SP  - 1
EP  - 8
ER  - 
TY  - CHAP
A1  - Waldmann, Christoph
A1  - Vera, Jean-Pierre de
A1  - Dachwald, Bernd
A1  - Strasdeit, Henry
A1  - Sohl, Frank
A1  - Hanff, Hendrik
A1  - Kowalski, Julia
A1  - Heinen, Dirk
A1  - Macht, Sabine
A1  - Bestmann, Ulf
A1  - Meckel, Sebastian
A1  - Hildebrandt, Marc
A1  - Funke, Oliver
A1  - Gehrt, Jan-Jöran
T1  - Search for life in ice-covered oceans and lakes beyond Earth
T2  - 2018 IEEE/OES Autonomous Underwater Vehicle Workshop, Proceedings November 2018, Article number 8729761
N2  - The quest for life on other planets is closely connected with the search for water in liquid state. Recent discoveries of deep oceans on icy moons like Europa and Enceladus have spurred an intensive discussion about how these waters can be accessed. The challenge of this endeavor lies in the unforeseeable requirements on instrumental characteristics both with respect to the scientific and technical methods. The TRIPLE/nanoAUV initiative is aiming at developing a mission concept for exploring exo-oceans and demonstrating the achievements in an earth-analogue context, exploring the ocean under the ice shield of Antarctica and lakes like Dome-C on the Antarctic continent.
KW  - Planetary exploration
KW  - Jupiter
KW  - ice moons
KW  - underwater vehicle
KW  - Antarctica
Y1  - 2018
U6  - http://dx.doi.org/10.1109/AUV.2018.8729761
ER  - 
TY  - CHAP
A1  - Wahle, Michael
T1  - Calculation of the response of heat exchanger tubes with regard to nonlinear and prestressing effects
T2  - Vibration in nuclear plant : proceedings of the 3rd International Conference on Vibration in Nuclear Plant held on 11 - 14 May 1982, Keswick ; vol. 1
Y1  - 1983
SN  - 0-7277-0192-4 (Druckausg.)
SN  - 978-0-7277-5270-3 (E-Book)
N1  - International Conference on Vibration in Nuclear Plant <3, 1982, Keswick>
N1  - Paper 1.10 (Log No. 71)
SP  - 162
EP  - 183
PB  - British Nuclear Energy Society
CY  - London
ER  - 
TY  - CHAP
A1  - Wahle, Michael
T1  - Determination of flow induced nonlinear vibrations of prestressed heat exchanger tubes
T2  - Advanced Course in Heat Exchangers : Theory and Practice ; ICHMT Symposium ; Dubrovnik, Croatia 1981. - (ICHMT digital library online ; 19)
Y1  - 1983
SP  - 339
EP  - 353
PB  - Begell House
CY  - Redding, Connecticut
ER  - 
TY  - CHAP
A1  - Veettil, Yadu Krishna Morassery
A1  - Rakshit, Shantam
A1  - Schopen, Oliver
A1  - Kemper, Hans
A1  - Esch, Thomas
A1  - Shabani, Bahman
ED  - Bin Abdollah, Mohd Fadzli
ED  - Amiruddin, Hilmi
ED  - Singh, Amrik Singh Phuman
ED  - Munir, Fudhail Abdul
ED  - Ibrahim, Asriana
T1  - Automated Control System Strategies to Ensure Safety of PEM Fuel Cells Using Kalman Filters
T2  - Proceedings of the 7th International Conference and Exhibition on Sustainable Energy and Advanced Materials (ICE-SEAM 2021), Melaka, Malaysia
N2  - Having well-defined control strategies for fuel cells, that can efficiently detect errors and take corrective action is critically important for safety in all applications, and especially so in aviation. The algorithms not only ensure operator safety by monitoring the fuel cell and connected components, but also contribute to extending the health of the fuel cell, its durability and safe operation over its lifetime. While sensors are used to provide peripheral data surrounding the fuel cell, the internal states of the fuel cell cannot be directly measured. To overcome this restriction, Kalman Filter has been implemented as an internal state observer.
Other safety conditions are evaluated using real-time data from every connected sensor and corrective actions automatically take place to ensure safety. The algorithms discussed in this paper have been validated thorough Model-in-the-Loop (MiL) tests as well as practical validation at a dedicated test bench.
KW  - control system
KW  - PEM fuel cells
KW  - Kalman filter
Y1  - 2022
SN  - 978-981-19-3178-9
SN  - 978-981-19-3179-6 (E-Book)
U6  - http://dx.doi.org/10.1007/978-981-19-3179-6_55
SN  - 2195-4356
N1  - The 7th International Conference and Exhibition on Sustainable Energy and Advanced Material (ICE-SEAM 2021) was organized by Universiti Teknikal Malaysia Melaka (UTeM), Malaysia, in association with the Universitas Sebelas Maret (UNS), Indonesia, on 23 November 2021
SP  - 296
EP  - 299
PB  - Springer Nature
CY  - Singapore
ER  - 
TY  - JOUR
A1  - Ulmer, Jessica
A1  - Braun, Carsten
A1  - Cheng, Chi-Tsun
A1  - Dowey, Steve
A1  - Wollert, Jörg
T1  - A human factors-aware assistance system in manufacturing based on gamification and hardware modularisation
JF  - International Journal of Production Research
N2  - Assistance systems have been widely adopted in the manufacturing sector to facilitate various processes and tasks in production environments. However, existing systems are mostly equipped with rigid functional logic and do not provide individual user experiences or adapt to their capabilities. This work integrates human factors in assistance systems by adjusting the hardware and instruction presented to the workers’ cognitive and physical demands. A modular system architecture is designed accordingly, which allows a flexible component exchange according to the user and the work task. Gamification, the use of game elements in non-gaming contexts, has been further adopted in this work to provide level-based instructions and personalised feedback. The developed framework is validated by applying it to a manual workstation for industrial assembly routines.
KW  - Human factors
KW  - assistance system
KW  - gamification
KW  - adaptive systems
KW  - manufacturing
Y1  - 2023
U6  - http://dx.doi.org/10.1080/00207543.2023.2166140
SN  - 0020-7543 (Print)
SN  - 1366-588X (Online)
PB  - Taylor & Francis
ER  - 
TY  - JOUR
A1  - Trilla, Joan
A1  - Grossen, Jürgen
A1  - Robinson, Alexander
A1  - Funke, Harald
A1  - Bosschaerts, Walter
A1  - Hendrick, Patrick
T1  - Development of a hydrogen combustion chamber for an ultra micro gas turbine
JF  - PowerMEMS 2008, 8th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, microEMS 2008, 2nd Symposium on Micro Environmental Machine Systems, Sendai, JP, Nov 9-12, 2008
Y1  - 2008
SP  - 101
EP  - 104
ER  - 
TY  - JOUR
A1  - Thomessen, Karolin
A1  - Thoma, Andreas
A1  - Braun, Carsten
T1  - Bio-inspired altitude changing extension to the 3DVFH* local obstacle avoidance algorithm
JF  - CEAS Aeronautical Journal
N2  - Obstacle avoidance is critical for unmanned aerial vehicles (UAVs) operating autonomously. Obstacle avoidance algorithms either rely on global environment data or local sensor data. Local path planners react to unforeseen objects and plan purely on local sensor information. Similarly, animals need to find feasible paths based on local information about their surroundings. Therefore, their behavior is a valuable source of inspiration for path planning. Bumblebees tend to fly vertically over far-away obstacles and horizontally around close ones, implying two zones for different flight strategies depending on the distance to obstacles. This work enhances the local path planner 3DVFH* with this bio-inspired strategy. The algorithm alters the goal-driven function of the 3DVFH* to climb-preferring if obstacles are far away. Prior experiments with bumblebees led to two definitions of flight zone limits depending on the distance to obstacles, leading to two algorithm variants. Both variants reduce the probability of not reaching the goal of a 3DVFH* implementation in Matlab/Simulink. The best variant, 3DVFH*b-b, reduces this probability from 70.7 to 18.6% in city-like worlds using a strong vertical evasion strategy. Energy consumption is higher, and flight paths are longer compared to the algorithm version with pronounced horizontal evasion tendency. A parameter study analyzes the effect of different weighting factors in the cost function. The best parameter combination shows a failure probability of 6.9% in city-like worlds and reduces energy consumption by 28%. Our findings demonstrate the potential of bio-inspired approaches for improving the performance of local path planning algorithms for UAV.
KW  - UAV
KW  - Obstacle avoidance
KW  - Autonomy
KW  - Local path planning
Y1  - 2023
U6  - http://dx.doi.org/10.1007/s13272-023-00691-w
SN  - 1869-5590 (Online)
SN  - 1869-5582 (Print)
N1  - Corresponding author: Karolin Thomessen
PB  - Springer
CY  - Wien
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  - http://dx.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  - 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  - http://dx.doi.org/10.2514/6.2023-2359
N1  - AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, MD & Online
PB  - AIAA
ER  - 
TY  - JOUR
A1  - Thoma, Andreas
A1  - Ravi, Sridhar
T1  - Significance of parallel computing on the performance of Digital Image Correlation algorithms in MATLAB
N2  - Digital Image Correlation (DIC) is a powerful tool used to evaluate displacements and deformations in a non-intrusive manner. By comparing two images, one of the undeformed reference state of a specimen and another of the deformed target state, the relative displacement between those two states is determined. DIC is well known and often used for post-processing analysis of in-plane displacements and deformation of specimen. Increasing the analysis speed to enable real-time DIC analysis will be beneficial and extend the field of use of this technique.
Here we tested several combinations of the most common DIC methods in combination with different parallelization approaches in MATLAB and evaluated their performance to determine whether real-time analysis is possible with these methods. To reflect improvements in computing technology different hardware settings were also analysed. We found that implementation problems can reduce the efficiency of a theoretically superior algorithm such that it becomes practically slower than a suboptimal algorithm. The Newton-Raphson algorithm in combination with a modified Particle Swarm algorithm in parallel image computation was found to be most effective. This is contrary to theory, suggesting that the inverse-compositional Gauss-Newton algorithm is superior. As expected, the Brute Force Search algorithm is the least effective method. We also found that the correct choice of parallelization tasks is crucial to achieve improvements in computing speed. A poorly chosen parallelisation approach with high parallel overhead leads to inferior performance. Finally, irrespective of the computing mode the correct choice of combinations of integerpixel and sub-pixel search algorithms is decisive for an efficient analysis. Using currently available hardware realtime analysis at high framerates remains an aspiration.
Y1  - 2019
SP  - 1
EP  - 17
ER  - 
TY  - CHAP
A1  - Thoma, Andreas
A1  - Fisher, Alex
A1  - Braun, Carsten
T1  - Improving the px4 avoid algorithm by bio-inspired flight strategies
T2  - DLRK2020 - „Luft- und Raumfahrt – Verantwortung in allen Dimensionen“
Y1  - 2020
N1  - Deutscher Luft- und Raumfahrtkongress 2020, 1. bis 3. September 2020 – Online, „Luft- und Raumfahrt – Verantwortung in allen Dimensionen“
ER  - 
TY  - CHAP
A1  - Thoma, Andreas
A1  - Fisher, Alex
A1  - Bertrand, Olivier
A1  - Braun, Carsten
ED  - Vouloutsi, Vasiliki
ED  - Mura, Anna
ED  - Tauber, Falk
ED  - Speck, Thomas
ED  - Prescott, Tony J.
ED  - Verschure, Paul F. M. J.
T1  - Evaluation of possible flight strategies for close object evasion from bumblebee experiments
T2  - Living Machines 2020: Biomimetic and Biohybrid Systems
KW  - Obstacle avoidance
KW  - Bumblebees
KW  - Flight control
KW  - UAV
KW  - MAV
Y1  - 2020
SN  - 978-3-030-64312-6
U6  - http://dx.doi.org/10.1007/978-3-030-64313-3_34
N1  - 9th International Conference, Living Machines 2020, Freiburg, Germany, July 28–30, 2020, Proceedings
SP  - 354
EP  - 365
PB  - Springer
CY  - Cham
ER  - 
TY  - CHAP
A1  - Thenent, N. E.
A1  - Dahmann, Peter
T1  - Increasing aircraft design flexibility ‐ The development of a hydrostatic transmission for gliders with self‐launching capability
T2  - Deutscher Luft- und Raumfahrtkongress 2011 : Bremen, 27. bis 29. September 2011 ; Tagungsband
Y1  - 2011
SN  - 978-3-9321-8274-7
SP  - 865
EP  - 883
PB  - Dt. Gesellschaft für Luft- und Raumfahrt
CY  - Bonn
ER  - 
TY  - CHAP
A1  - Thenent, N. E.
A1  - Dahmann, Peter
T1  - Hydrostatic propeller drive
T2  - Proceedings of the conference : 18 - 20 May, 2011 Tampere, Finland / the Twelth Scandinavian International Conference on Fluid Power, SICFP'11. Ed.: Harri Sairiala ... Vol. 1
Y1  - 2011
SN  - 978-952-15-2517-9
SP  - 217
EP  - 227
CY  - Tampere
ER  - 
TY  - JOUR
A1  - Tekin, Nurettin
A1  - Ashikaga, Mitsugu
A1  - Horikawa, Atsushi
A1  - Funke, Harald
T1  - Enhancement of fuel flexibility of industrial gas turbines by development of innovative hydrogen combustion systems
JF  - Gas for energy
N2  - For fuel flexibility enhancement hydrogen represents a possible alternative gas turbine fuel within future low emission power generation, in case of hydrogen production by the use of renewable energy sources such as wind energy or biomass. Kawasaki Heavy Industries, Ltd. (KHI) has research and development projects for future hydrogen society; production of hydrogen gas, refinement and liquefaction for transportation and storage, and utilization with gas turbine / gas engine for the generation of electricity. In the development of hydrogen gas turbines, a key technology is the stable and low NOx hydrogen combustion, especially Dry Low Emission (DLE) or Dry Low NOx (DLN) hydrogen combustion. Due to the large difference in the physical properties of hydrogen compared to other fuels such as natural gas, well established gas turbine combustion systems cannot be directly applied for DLE hydrogen combustion. Thus, the development of DLE hydrogen combustion technologies is an essential and challenging task for the future of hydrogen fueled gas turbines. The DLE Micro-Mix combustion principle for hydrogen fuel has been in development for many years to significantly reduce NOx emissions. This combustion principle is based on cross-flow mixing of air and gaseous hydrogen which reacts in multiple miniaturized “diffusion-type” flames. The major advantages of this combustion principle are the inherent safety against flashback and the low NOx-emissions due to a very short residence time of the reactants in the flame region of the micro-flames.
Y1  - 2018
IS  - 2
PB  - Vulkan-Verlag
CY  - Essen
ER  - 
TY  - CHAP
A1  - Tamaldin, Noreffendy
A1  - Mansor, Muhd Rizuan
A1  - Mat Yamin, Ahmad Kamal
A1  - Bin Abdollah, Mohd Fazli
A1  - Esch, Thomas
A1  - Tonoli, Andrea
A1  - Reisinger, Karl Heinz
A1  - Sprenger, Hanna
A1  - Razuli, Hisham
ED  - Bin Abdollah, Mohd Fadzli
ED  - Amiruddin, Hilmi
ED  - Singh, Amrik Singh Phuman
ED  - Munir, Fudhail Abdul
ED  - Ibrahim, Asriana
T1  - Development of UTeM United Future Fuel Design Training Center Under Erasmus+ United Program
T2  - Proceedings of the 7th International Conference and Exhibition on Sustainable Energy and Advanced Materials (ICE-SEAM 2021), Melaka, Malaysia
N2  - The industrial revolution IR4.0 era have driven many states of the art technologies to be introduced especially in the automotive industry. The rapid development of automotive industries in Europe have created wide industry gap between European Union (EU) and developing countries such as in South-East Asia (SEA). Indulging this situation, FH Joanneum, Austria together with European partners from FH Aachen, Germany and Politecnico Di Torino, Italy is taking initiative to close the gap utilizing the Erasmus+ United grant from EU. A consortium was founded to engage with automotive technology transfer using the European  ramework to Malaysian, Indonesian and Thailand Higher Education Institutions (HEI) as well as automotive industries. This could be achieved by establishing Engineering Knowledge Transfer Unit (EKTU) in respective SEA institutions guided by the industry partners in their respective countries. This EKTU could offer updated, innovative, and high-quality training courses to increase graduate’s employability in higher education institutions and strengthen relations between HEI and the wider economic and social environment by addressing Universityindustry cooperation which is the regional priority for Asia. It is expected that, the Capacity Building Initiative would improve the quality of higher education and enhancing its relevance for the labor market and society in the SEA partners. The outcome of this project would greatly benefit the partners in strong and complementary partnership targeting the automotive industry and enhanced larger scale international cooperation between the European and SEA partners. It would also prepare the SEA HEI in sustainable partnership with Automotive industry in the region as a mean of income generation in the future.
KW  - Erasmus+ United
KW  - technology transfer
KW  - UTeM Engineering Knowledge Transfer Unit
KW  - Malaysian automotive industry
Y1  - 2022
SN  - 978-981-19-3178-9
SN  - 978-981-19-3179-6 (E-Book)
U6  - http://dx.doi.org/10.1007/978-981-19-3179-6_50
SN  - 2195-4356
N1  - The 7th International Conference and Exhibition on Sustainable Energy and Advanced Material (ICE-SEAM 2021) was organized by Universiti Teknikal Malaysia Melaka (UTeM), Malaysia, in association with the Universitas Sebelas Maret (UNS), Indonesia, on 23 November 2021.
SP  - 274
EP  - 278
PB  - Springer Nature
CY  - Singapore
ER  - 
TY  - CHAP
A1  - Tamaldin, Noreffendy
A1  - Esch, Thomas
A1  - Tonoli, Andrea
A1  - Reisinger, Karl Heinz
A1  - Sprenger, Hanna
A1  - Razuli, Hisham
T1  - ERASMUS+ United CBHE Automotive International Collaboration from European to South East Asia
T2  - Proceedings of the 2nd African International Conference on Industrial Engineering and Operations Management
N2  - The industrial revolution especially in the IR4.0 era have driven many states of the art technologies to be introduced.
The automotive industry as well as many other key industries have also been greatly influenced. The rapid development of automotive industries in Europe have created wide industry gap between European Union (EU) and developing countries such as in South East Asia (SEA). Indulging this situation, FH JOANNEUM, Austria together with European partners from FH Aachen, Germany and Politecnico di Torino, Italy are taking initiative to close down the gap utilizing the Erasmus+ United Capacity Building in Higher Education grant from EU. A consortium was founded to engage with automotive technology transfer using the European framework to Malaysian, Indonesian and Thailand Higher Education Institutions (HEI) as well as automotive industries in respective countries. This could be achieved by establishing Engineering Knowledge Transfer Unit (EKTU) in respective SEA institutions guided by the industry partners in their respective countries. This EKTU could offer updated, innovative and high-quality training courses to increase graduate’s employability in higher education institutions and strengthen relations between HEI and the wider economic and social environment by addressing University-industry cooperation which is the regional priority for Asia. It is expected that, the Capacity Building Initiative would improve the quality of higher education and enhancing its relevance for the labor market and society in the SEA partners. The outcome of this project would greatly benefit the partners in strong and complementary partnership targeting the automotive industry and enhanced larger scale international cooperation between the European and SEA partners. It would also prepare the SEA HEI in sustainable partnership with Automotive industry in the region as a mean of income generation in the future.
KW  - European Framework and South East Asia
KW  - Technology Transfer
KW  - Capacity Building Higher Education
KW  - Malaysian Automotive Industry
Y1  - 2020
SN  - 978-1-7923-6123-4
SN  - 2169-8767
N1  - 2nd African International Conference on Industrial Engineering and Operations Management; Harare, Zimbabwe, December 7-10, 2020
SP  - 2970
EP  - 2972
PB  - IEOM Society International
CY  - Southfield
ER  - 
TY  - CHAP
A1  - Striegan, Constantin J. D.
A1  - Struth, Benjamin
A1  - Dickhoff, Jens
A1  - Kusterer, Karsten
A1  - Funke, Harald
A1  - Bohn, Dieter
T1  - Numerical Simulations of the Micromix DLN Hydrogen Combustion Technology with LES and Comparison to Results of RANS and Experimental Data
T2  - Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan.
Y1  - 2019
SN  - 978-4-89111-010-9
N1  - IGCT-2019-147
SP  - 1
EP  - 9
ER  - 
TY  - CHAP
A1  - Striegan, C.
A1  - Haj Ayed, A.
A1  - Funke, Harald
A1  - Loechle, S.
A1  - Kazari, M.
A1  - Horikawa, A.
A1  - Okada, K.
A1  - Koga, K.
T1  - Numerical combustion and heat transfer simulations and validation for a hydrogen fueled "micromix" test combustor in industrial gas turbine applications
T2  - Proceedings of the ASME Turbo Expo
Y1  - 2017
SN  - 978-079185085-5
U6  - http://dx.doi.org/10.1115/GT2017-64719
N1  - ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition, GT 2017; Charlotte; United States; 26 June 2017 through 30 June 2017
IS  - Volume Part F130041-4B, 2017
ER  - 
TY  - JOUR
A1  - Stiemer, Luc Nicolas
A1  - Thoma, Andreas
A1  - Braun, Carsten
T1  - MBT3D: Deep learning based multi-object tracker for bumblebee 3D flight path estimation
JF  - PLoS ONE
N2  - This work presents the Multi-Bees-Tracker (MBT3D) algorithm, a Python framework implementing a deep association tracker for Tracking-By-Detection, to address the challenging task of tracking flight paths of bumblebees in a social group. While tracking algorithms for bumblebees exist, they often come with intensive restrictions, such as the need for sufficient lighting, high contrast between the animal and background, absence of occlusion, significant user input, etc. Tracking flight paths of bumblebees in a social group is challenging. They suddenly adjust movements and change their appearance during different wing beat states while exhibiting significant similarities in their individual appearance. The MBT3D tracker, developed in this research, is an adaptation of an existing ant tracking algorithm for bumblebee tracking. It incorporates an offline trained appearance descriptor along with a Kalman Filter for appearance and motion matching. Different detector architectures for upstream detections (You Only Look Once (YOLOv5), Faster Region Proposal Convolutional Neural Network (Faster R-CNN), and RetinaNet) are investigated in a comparative study to optimize performance. The detection models were trained on a dataset containing 11359 labeled bumblebee images. YOLOv5 reaches an Average Precision of AP = 53, 8%, Faster R-CNN achieves AP = 45, 3% and RetinaNet AP = 38, 4% on the bumblebee validation dataset, which consists of 1323 labeled bumblebee images. The tracker’s appearance model is trained on 144 samples. The tracker (with Faster R-CNN detections) reaches a Multiple Object Tracking Accuracy MOTA = 93, 5% and a Multiple Object Tracking Precision MOTP = 75, 6% on a validation dataset containing 2000 images, competing with state-of-the-art computer vision methods. The framework allows reliable tracking of different bumblebees in the same video stream with rarely occurring identity switches (IDS). MBT3D has much lower IDS than other commonly used algorithms, with one of the lowest false positive rates, competing with state-of-the-art animal tracking algorithms. The developed framework reconstructs the 3-dimensional (3D) flight paths of the bumblebees by triangulation. It also handles and compares two alternative stereo camera pairs if desired.
Y1  - 2023
U6  - http://dx.doi.org/10.1371/journal.pone.0291415
SN  - 1932-6203
N1  - Corresponding author: Luc Nicolas Stiemer
VL  - 18
IS  - 9
PB  - PLOS
CY  - San Fancisco
ER  -