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Design Approach for Secure Networks to Introduce Data Analytics within the Aircraft Cabin

Hamburg University of Technology-Hartmut Hintze, Fabian Giertzsch, Ralf God
Published 2019-09-16 by SAE International in United States
In the past, aircraft network design did not demand for information security considerations. The aircraft systems were simple, obscure, proprietary and, most importantly for security, the systems have been either physically isolated or they have been connected by directed communication links. The union of the aircraft systems thus formed a federated network. These properties are in sharp contrast with today’s system designs, which rest upon platform-based solutions with shared resources being interconnected by a massively meshed and shared communication network. The resulting connectivity and the high number of interfaces require an in-depth security analysis as the systems also provide functions that are required for the safe operation of the aircraft. This network design evolution, however, resulted in an iterative and continuous adaption of existing network solutions as these have not been developed from scratch. Now, with the upcoming trend of data analytics and artificial intelligence applications, which demand for an extensive availability of data, holistic aircraft cabin networks are necessary to satisfy the associated requirements. For the development of such networks this paper proposes a…
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Local Weakening of Honeycomb Core for Improved Surface Quality and Bonding in Co-Cured Sandwich Panels

Hamburg University of Technology-Henrik Eschen, Thorsten Schüppstuhl
Published 2019-09-16 by SAE International in United States
Sandwich panels made of Nomex honeycomb core and fiber reinforced face sheets are a major component of aircraft interior parts. A common way to locally increase the strength of such panels, e.g. for load introduction, is the local thickening of the face sheets with additional prepreg layers. Curing of strengthened panels without further processing of the core leads to higher flatness tolerances as well as residual stresses. Machining of the core in the strengthened areas is possible, but expensive due to high machine costs and additional cleaning processes. In this paper a new process for the reduction of the residual stresses in strengthened areas, as well as improved bonding between core and face sheets is presented. The process is based on local reduction of the compressive strength in the surface area of the honeycomb core, which allows for controlled, irreversible deformation at curing pressure. For the reduction of compressive strength, a concept based on a robot guided tool with multiple blades is presented. The process parameters impacting the compressive strength after weakening are derived based…
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Mobile Laser Trackers for Aircraft Manufacturing: Increasing Accuracy and Productivity of Robotic Applications for Large Parts

Hamburg University of Technology-Wolfgang Hintze, Jörg Wollnack
FFT Produktionssysteme GmbH & Co KG-Fabian Ehmke
Published 2019-03-19 by SAE International in United States
The demand for higher production rates of large parts in aircraft industry requests more flexible manufacturing solutions. High-accurate mobile robots show a promising alternative in comparison with high-invest special machines. With mobile robot-based solutions processes can be executed simultaneously which increases the productivity significantly. However, the freedom of mobility results in insufficient positioning accuracy of these machines. Hence fast and accurate referencing processes are required to achieve cost-effectiveness and meet production tolerances. In this publication a Mobile Laser Tracker (MLT) system and a holistic approach for future manufacturing systems with mobile robots will be introduced and discussed.
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Real-Time Path Correction of an Industrial Robot for Adhesive Application on Composite Structures

Hamburg University of Technology-Jörg Wollnack
Fraunhofer IFAM-Nihar Hasmukhbhai Shah, Shivaprakash Subramanian
Published 2018-04-03 by SAE International in United States
Due to their unique and favorable properties as well as high strength to weight ratio, composite materials are finding increasing applications in automotive, aircraft and other vehicle manufacturing industries. High demand, production rates and increasing part complexity, together with design variations require fast, flexible and fully automated assembly techniques. In automotive and aircraft manufacturing, widely used bonding and sealing processes are automated using industrial robots due to their speed, flexibility and large working volume. However, there are limitations in achieving complete automation of these processes due to the inherent inaccuracies of the industrial robots, workpiece positioning and process tolerances. Currently, the robot programs are generated in CAD/CAM environment and are adjusted manually according to the actual workpiece. An alternate solution is proposed with an on-board vision based sensor setup to adapt the robot path compensating for the robot kinematic inaccuracies, workpiece referencing errors and unique local deformations of the workpiece via a real-time interface. The realized setup consists of a prototype dosing system with two laser line triangulation sensors on the end-effector of a serial robot.…
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Electromagnetic Compatibility (EMC) of Electronic Devices with Near Field Communication (NFC) for Use in Aircraft

Hamburg University of Technology-Thorsten Kiehl, Jan Philip Speichert, Ethan Higgins, Ralf God
Published 2017-09-19 by SAE International in United States
For an “end-to-end passenger experience that is secure, seamless and efficient” the International Air Transport Association (IATA) proposes Near Field Communication (NFC) and a single token concept to be enablers for future digital travel. NFC is a wireless technology commonly utilized in Portable Electronic Devices (PEDs) and contactless smart cards. It is characterized by the following two attributes: a tangible user interface and secured short range communication. While manufacturers are currently adapting PED settings to enable NFC in the flight mode, the integration and use of this technology in aircraft cabins still remains a challenge. There are no explicit qualification guidelines for electromagnetic compatibility (EMC) testing in an aircraft environment available and there is a lack of a detailed characterization of NFC equipped PEDs. To overcome this challenge and exceeding the work of earlier publications, in this paper a simulation model combined with a measurement setup is utilized for exhaustive characterization of NFC equipped PEDs. In the first instance a well-documented NFC development board with characteristics representative for commercial PEDs is used. This enables the…
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Referencing Strategies for High Accuracy Machining of Large Aircraft Components with Mobile Robotic Systems

Hamburg University of Technology-Jörg Wollnack, Wolfgang Hintze
Fraunhofer IFAM-Hendrik Susemihl, Christoph Brillinger, Sven Philipp Stürmer, Stephan Hansen, Christian Boehlmann, Simon Kothe
Published 2017-09-19 by SAE International in United States
The demand for higher production rates in aircraft industry requests more flexible manufacturing solutions. A bottleneck in production is the machining of large components by vast portal machines. Time-consuming referencing processes result in non-satisfying cost-effectiveness of these high-invest-machines. Mobile robot-based solutions are able to operate simultaneously which increases the productivity significantly. However, due to the limited workspace of robots, machining tasks have to be divided and long trajectories are separated in single overlapping segments. Thus high-accuracy referencing strategies are required to achieve desired production tolerances. In this publication different advanced optical reference strategies will be discussed taking the inhomogeneous behavior of a mobile robotic machining system into account. Investigations on the absolute positioning and the machining accuracy will show the impact of different referencing strategies on sub-scale machining especially for large work spaces.
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Accuracy Analysis and Error Source Identification for Optimization of Robot Based Machining Systems for Aerospace Production

Hamburg University of Technology-Jörg Wollnack, Wolfgang Hintze
Fraunhofer IFAM-Simon Kothe, Sven Philipp von Stürmer, Hans Christian Schmidt, Christian Boehlmann
Published 2016-09-27 by SAE International in United States
Strong market growth, upcoming global competition and the impact of customer-requirements in aerospace industry demand for more productive, flexible and cost-effective machining systems. Industrial robots have already demonstrated their advantages in smart and efficient production in a wide field of applications and industries. However, their use for machining of structural aircraft components is still obstructed by the disadvantage of low absolute accuracy and adverse reaction to process loads. This publication demonstrates and investigates different methods for performance assessment and optimization of robot-based machining systems. For conventional Cartesian CNC machining systems several methods and guidelines for performance assessment and error identification are available. Due to the attributes of a common 6-axis-robot serial kinematics these methods of decoupled and separated analysis fail, especially concerning optimization of the system. One main focus of this paper lies on a new performance assessment strategy that in contrast to conventional methods neither needs a machining process nor an additional measurement system. Nevertheless it can be combined with these methods to provide even better results. By plotting the robots encoder during movement,…
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Virtual Integration of an All-Electric Flight Control System Architecture and the Aircraft Electrical Power Distribution Network

Hamburg University of Technology-Tobias Kreitz, Frank Thielecke
Published 2016-09-20 by SAE International in United States
The aviation industry is facing major challenges due to increased environmental requirements that are driven by economic constraints. For this reason, guidelines like "Flightpath 2050", the official guide of European aviation, call for significant reductions in pollutant emissions. The concept of the More Electric Aircraft offers promising perspectives to meet these demands. A key-enabler for this concept is the integration of new technologies on board of the next generation of civil transportation aircraft. Examples are electro-mechanical actuators for primary and secondary flight controls or the fuel cell technology as innovative electrical energy supply system. Due to the high complexity and interdisciplinarity, the development of such systems is an equally challenging and time-consuming process. To support the classical development process, a continuous model-based approach for the design and test of complex aircraft systems is currently developed at the Hamburg University of Technology. In addition to the computer-aided engineering, this approach includes the implementation of virtual integration studies at the system level. This feature provides the opportunity for an early execution of performance evaluations to assess the…
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Simulation-Driven Methodology for the Requirements Verification and Safety Assessment of Innovative Flight Control Systems

Hamburg University of Technology-Tobias Kreitz, Riko Bornholdt, Matthias Krings, Karsten Henning, Frank Thielecke
Published 2015-09-15 by SAE International in United States
The paradigm shift to focus on an enhancement of existing aircraft systems raises the question which of the many possible incremental improvements results in an advantageous solution still considering all existing requirements. Hence, new methodologies for aircraft system design are a prerequisite to cope with such huge and complex design spaces. In the case of flight control system optimization, major design variables are the control surface configuration and actuation as well as their functional allocation. Possible architecture topologies have to be verified inter alia with respect to system safety requirements. In this context, flight dynamic characteristics and handling qualities of the fully operational as well as of several degraded system states of each topology have to be evaluated and checked against common specifications.A model-based verification of the requirements is favorable, resulting in a rapid reduction of the design space. Safety objectives for valid configurations are derived and serve as an input for a subsequent safety assessment. This two-step methodology, a simulation-driven verification of handling quality requirements and a corresponding safety assessment, is presented in this…
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Towards Operationally Robust Fuel Cell Systems for Aeronautical Applications

Hamburg University of Technology-Hendrik Strummel, Frank Thielecke
Published 2015-09-15 by SAE International in United States
Fuel cell technology will play a decisive role in the process of achieving the ambitious ecological goals of the aviation industry. However, apart from its obvious environmental advantages, the integration of fuel cell technology into commercial aircraft represents a challenging task in terms of operational and economical aspects.Since fuel cell systems are currently exposed to an intense competition with well-established power sources onboard an aircraft, engineers are in pursuit of highly efficient and particularly lightweight fuel cell systems. Supported by model-based design in conjunction with elaborate optimization techniques this pursuit has led to highly specialized systems. These systems tend to use their components to full capacity, which typically implies marginal system robustness. In consequence, preliminary design studies propose fuel cell systems that are sensitive to partial faults, or even to the slightest deviation, or degradation of their components' behavior.Non-functional requirements such as reliability, availability, dispatchability and durability will become key factors for the acceptance of fuel cells as alternative power sources onboard aircraft. These requirements demand the taking of coordinated measures in both Systems Architecting…
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