TY - CHAP A1 - Schleupen, Josef A1 - Engemann, Heiko A1 - Bagheri, Mohsen A1 - Kallweit, Stephan A1 - Dahmann, Peter T1 - Developing a climbing maintenance robot for tower and rotor blade service of wind turbines T2 - Advances in Robot Design and Intelligent Control : Proceedings of the 25th Conference on Robotics in Alpe-Adria-Danube Region (RAAD16) Y1 - 2017 SN - 978-3-319-49058-8 U6 - https://doi.org/10.1007/978-3-319-49058-8_34 N1 - Advances in Robot Design and Intelligent Control ; Vol. 540 SP - 310 EP - 319 PB - Springer CY - Cham ER - TY - CHAP A1 - Hartmann, Axel A1 - Kallweit, Stephan A1 - Feldusen, Antje A1 - Schröder, Wolfgang T1 - Detection of upstream propagating sound waves at buffet flow using high-speed PIV BT - 16th International Symposium on Applications of Laser Techniques to Fluid Mechanics ; 9th to 12th July 2012 Lisbon, Portugal Y1 - 2012 N1 - Aerodynamisches Institut ; International Symposium on Applications of Laser Techniques to Fluid Mechanics <16, 2012, Lissabon> ER - TY - JOUR A1 - Franko, Josef A1 - Du, Shengzhi A1 - Kallweit, Stephan A1 - Duelberg, Enno Sebastian A1 - Engemann, Heiko T1 - Design of a Multi-Robot System for Wind Turbine Maintenance JF - Energies N2 - The maintenance of wind turbines is of growing importance considering the transition to renewable energy. This paper presents a multi-robot-approach for automated wind turbine maintenance including a novel climbing robot. Currently, wind turbine maintenance remains a manual task, which is monotonous, dangerous, and also physically demanding due to the large scale of wind turbines. Technical climbers are required to work at significant heights, even in bad weather conditions. Furthermore, a skilled labor force with sufficient knowledge in repairing fiber composite material is rare. Autonomous mobile systems enable the digitization of the maintenance process. They can be designed for weather-independent operations. This work contributes to the development and experimental validation of a maintenance system consisting of multiple robotic platforms for a variety of tasks, such as wind turbine tower and rotor blade service. In this work, multicopters with vision and LiDAR sensors for global inspection are used to guide slower climbing robots. Light-weight magnetic climbers with surface contact were used to analyze structure parts with non-destructive inspection methods and to locally repair smaller defects. Localization was enabled by adapting odometry for conical-shaped surfaces considering additional navigation sensors. Magnets were suitable for steel towers to clamp onto the surface. A friction-based climbing ring robot (SMART— Scanning, Monitoring, Analyzing, Repair and Transportation) completed the set-up for higher payload. The maintenance period could be extended by using weather-proofed maintenance robots. The multi-robot-system was running the Robot Operating System (ROS). Additionally, first steps towards machine learning would enable maintenance staff to use pattern classification for fault diagnosis in order to operate safely from the ground in the future. Y1 - 2020 U6 - https://doi.org/10.3390/en13102552 SN - 1996-1073 VL - 13 IS - 10 SP - Article 2552 PB - MDPI CY - Basel ER - TY - JOUR A1 - Grundmann, Reinhard T1 - Design Criteria for Aeroacoustic Wind Tunnels Y1 - 1992 N1 - Konferenzeinzelbericht : DGLR-workshop : Joint meeting of the Specialists Groups Test Facilities/Aeroacoustics - Flight Noise . Deutsche Gesellschaft für Luft- und Raumfahrt. Test Facilities Specialist Group ; Deutsche Gesellschaft für Luft- und Raumfahr ER - TY - JOUR A1 - Abbas, Karim A1 - Balc, Nicolae A1 - Bremen, Sebastian A1 - Skupin, Marco T1 - Crystallization and aging behavior of polyetheretherketone PEEK within rapid tooling and rubber molding JF - Journal of Manufacturing and Materials Processing N2 - In times of short product life cycles, additive manufacturing and rapid tooling are important methods to make tool development and manufacturing more efficient. High-performance polymers are the key to mold production for prototypes and small series. However, the high temperatures during vulcanization injection molding cause thermal aging and can impair service life. The extent to which the thermal stress over the entire process chain stresses the material and whether it leads to irreversible material aging is evaluated. To this end, a mold made of PEEK is fabricated using fused filament fabrication and examined for its potential application. The mold is heated to 200 ◦C, filled with rubber, and cured. A differential scanning calorimetry analysis of each process step illustrates the crystallization behavior and first indicates the material resistance. It shows distinct cold crystallization regions at a build chamber temperature of 90 ◦C. At an ambient temperature above Tg, crystallization of 30% is achieved, and cold crystallization no longer occurs. Additional tensile tests show a decrease in tensile strength after ten days of thermal aging. The steady decrease in recrystallization temperature indicates degradation of the additives. However, the tensile tests reveal steady embrittlement of the material due to increasing crosslinking. KW - additive manufacturing KW - fused filament fabrication KW - crystallization KW - polyetheretherketone KW - rapid tooling Y1 - 2022 U6 - https://doi.org/10.3390/jmmp6050093 SN - 2504-4494 N1 - The article belongs to the Special Issue Advances in Injection Molding: Process, Materials and Applications VL - 6 IS - 5 SP - 1 EP - 12 PB - MDPI CY - Basel ER - TY - JOUR A1 - Kämper, Klaus-Peter A1 - Schmitt, W. A1 - Güntherodt, G. A1 - Gambino, R. J. T1 - CrO2—A New Half-Metallic Ferromagnet? Kämper, K.-P.; Schmitt, W.; Güntherodt, G.; Gambino, R. J., Ruf, R. JF - Physical Review Letters. 59 (1987), H. 24 Y1 - 1987 SN - 1079-7114 SP - 2788 EP - 2791 ER - TY - JOUR A1 - Enning, Manfred A1 - Stützle, Thorsten A1 - Viereck, Uwe A1 - Stribersky, Anton T1 - Creepage control for use in wheelslide protection systems / Stützle, Thorsten ; Viereck, Uwe ; Stribersky, Anton ; Rulka, Wolfgang ; Enning, Manfred ; Abel, Dirk JF - Control in transportation systems : proceedings of the 11th IFAC symposium on control in transportation systems (CTS 2006), August 29-31, 2006, Delft, the Netherlands / International Federation of Automatic Control Y1 - 2006 SN - 0742-5953 ER - TY - CHAP A1 - Wollert, Jörg A1 - Plessmann, K. W. T1 - Controlling processes by operating-point based hybride observers T2 - EUFIT '93 : September 7 - 10, 1993, Eurogress Aachen, Germany, proceedings / First European Congress on Fuzzy and Intelligent Technologies Y1 - 1993 SN - 3-86073-176-9 SP - 1151 EP - 1155 PB - Verl. d. Augustinus Buchh. CY - Aachen ER - TY - CHAP A1 - Beer, Stefan A1 - Haidn, O.J. A1 - Willms, Herbert ED - Carvalho, Maria da Graça T1 - Control of stoichiometric propellant supply in an H2/O2-spinning reserve system T2 - Combustion technologies for a clean environment : selected papers from the proceedings of the first international conference, Vilamoura, Portugal, September 3 - 6, 1991. - (Energy, combustion and the environment ;1) Y1 - 1995 SN - 2-88124-619-2 SP - 825 EP - 838 PB - Gordon and Breach CY - Basel [u.a.] ER - TY - CHAP A1 - Pfaff, Raphael A1 - Shahidi, Parham A1 - Enning, Manfred T1 - Connected freight rail rolling stock: a modular approach integrating sensors, actors and cyber physical systems for operational advantages and condition based maintenance T2 - Asia-Pacific Conference of the Prognostics and Health Management Society Y1 - 2017 N1 - Asia-Pacific Conference of the Prognostics and Health Management Society, Jeju, Korea 2017 SP - 1 EP - 7 ER -