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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  -