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Viewing 1 to 30 of 976
2016-10-25
Technical Paper
2016-36-0377
Alain Giacobini Souza, Luiz Carlos Gadelha Souza
Abstract In designing of the Attitude Control System (ACS) is important take into account the influence of the structure’s flexibility, since they can interact with the satellite rigid motion, mainly, during translational and/or rotational maneuver, damaging the ACS pointing accuracy. In the linearization and reduction of the rigid-flexible satellite mathematic model, usually one loses some important information associated with the satellite true dynamical behavior. One way to recovery this information is include to the ACS design parametric and not parametric uncertainties of the system. The H infinity control method is able to take into account the parametric uncertainty in the control law design, so the controller becomes more robust. This paper presents the design of a robust controller using the H infinity control technique to control the attitude of a rigid-flexible satellite.
2016-09-20
Technical Paper
2016-01-1980
Syama M. Rao, Dineshkumar M
Abstract This paper studies admissible state trajectories for an unmanned aerial vehicle(UAV) by performing dynamic soaring technique in the wind gradient. An optimization problem is formulated by employing direct optimal piece wise control. A 3-DOF point mass model system dynamics of UAV is considered. The bank angle and lift co-efficient are identified as control variables. A UAV of mass 5.44kg is considered for this study. Performance measures considered are maximization of specific energy and maximization of specific energy rate extracted by the vehicle, and minimization of the control effort. The effects of linear and parabolic wind gradient on maximizing the specific energy of an autonomous dynamic soaring UAV is also studied and minimum linear gradient required is found. The loop radius of the loiter pattern is maximized for applications like surveillance and patrolling of a localized area along with energy maximization as objective function.
2016-09-20
Technical Paper
2016-01-2034
Tobias Kreitz, Frank Thielecke
Abstract 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.
2016-09-20
Technical Paper
2016-01-2039
Prashant S. Vadgaonkar, Ullas Janardhan
Avionics industry is moving towards fly-by wire aircrafts with less reliance on mechanical systems leading to increase in the complexity of in-flight hardware elements. RTCA/DO-254 and EUROCAE ED-80 plays a vital role in the design assurance of airborne electronic hardware. RTCA/ DO-254 and EUROCAE ED-80 are the industry standards for Design Assurance Guidance for Airborne Electronic Hardware. The two different agencies FAA and EU regulate and apply this design assurance guidance to the regulatory law in CFR and EASA CS respectively. This paper discusses the need for DO-254 /ED-80 certification in Aerospace industry, the advantages and benefits to the avionics manufacturers. The paper presents the study made on similarities and differences between DO-254/ED-80.
2016-09-20
Technical Paper
2016-01-2052
Virgilio Valdivia-Guerrero, Ray Foley, Stefano Riverso, Parithi Govindaraju, Atiyah Elsheikh, Leonardo Mangeruca, Gilberto Burgio, Alberto Ferrari, Marcel Gottschall, Torsten Blochwitz, Serge Bloch, Danielle Taylor, Declan Hayes-McCoy, Andreas Himmler
Abstract This paper presents an overview of a project called “Modelling and Simulation Tools for Systems Integration on Aircraft (MISSION)”. This is a collaborative project being developed under the European Union Clean Sky 2 Program, a public-private partnership bringing together aeronautics industrial leaders and public research organizations based in Europe. The provision of integrated modeling, simulation, and optimization tools to effectively support all stages of aircraft design remains a critical challenge in the Aerospace industry. In particular the high level of system integration that is characteristic of new aircraft designs is dramatically increasing the complexity of both design and verification. Simultaneously, the multi-physics interactions between structural, electrical, thermal, and hydraulic components have become more significant as the systems become increasingly interconnected.
2016-09-20
Technical Paper
2016-01-2069
Zied Aloui, Nawfal Ahamada, Julien Denoulet, Martin Rayrole, Francine Pierre, Marc Gatti
Abstract Avionics is one kind of domain where prevention prevails. Nonetheless failures occur, sometimes due to pilot misreacting, flooded in information. Sometimes information itself would be better verified than trusted. To avoid some kind of failure, it has been thought to add,in midst of the ARINC664 aircraft data network, a new kind of monitoring.
2016-09-20
Technical Paper
2016-01-2067
Qingchuan Shi, Kartik Lakshminarashimhan, Christopher Noll, Eelco Scholte, Omer Khan
Abstract Modern aircraft systems employ numerous processors to achieve system functionality. In particular, engine controls and power distribution subsystems rely heavily on software to provide safety-critical functionality, and are expected to move towards multicore architectures. The computing hardware-layer of avionic systems must be able to execute many concurrent workloads under tight deterministic execution guarantees to meet the safety standards. Single-chip multicores are attractive for safety-critical embedded systems due to their lightweight form factor. However, multicores aggressively share hardware resources, leading to interference that in turn creates non-deterministic execution for multiple concurrent workloads. We propose an approach to remove on-chip interference via a set of methods to spatio-temporally partition shared multicore resources.
2016-09-20
Journal Article
2016-01-2051
Andreas Himmler, Lars Stockmann, Dominik Holler
Abstract The application of a communication infrastructure for hybrid test systems is currently a topic in the aerospace industry, as also in other industries. One main reason is flexibility. Future laboratory tests means (LTMs) need to be easier to exchange and reuse than they are today. They may originate from different suppliers and parts of them may need to fulfill special requirements and thus be based on dedicated technologies. The desired exchangeability needs to be achieved although suppliers employ different technologies with regard to specific needs. To achieve interoperability, a standardized transport mechanism between test systems is required. Designing such a mechanism poses a challenge as there are several different types of data that have to be exchanged. Simulation data is a prominent example. It has to be handled differently than control data, for example. No one technique or technology fits perfectly for all types of data.
2016-04-05
Journal Article
2016-01-0400
Xuqian Jiang, Hailing Luo, Yong Xia, Qing Zhou
Abstract As mechanical damage induced thermal runaway of lithium-ion batteries has become one of the research hotspots, it is quite crucial to understand the mechanical behavior of component materials of lithium battery. This study focuses on the mechanical performance of separators and electrodes under different loading conditions and the error sources analysis for test results. Uniaxial tensile tests were conducted under both quasi-static and dynamic loading conditions. The strain was acquired through the combination of high speed camera and digital image correlation (DIC) method while the force was obtained with a customized load cell. Noticeable anisotropy and strain rate effect were observed for separators. The fracture mode of separators is highly correlated to the microscopic fiber orientation. To demonstrate the correlation microscopic images of separator material were obtained through SEM to match the facture edges of tensile tests at different loading directions.
2015-09-15
Technical Paper
2015-01-2471
Alessandro Ceruti, Simone Curatolo, Alessandro Bevilacqua, Piergiovanni Marzocca
Abstract The maturity reached in the development of Unmanned Air Vehicles (UAVs) systems is making them more and more attractive for a vast number of civil missions. Clearly, the introduction of UAVs in the civil airspace requiring practical and effective regulation is one of the most critical issues being currently discussed. As several civil air authorities report in their regulations “Sense and Avoid” or “Detect and Avoid” capabilities are critical to the successful integration of UAV into the civil airspace. One possible approach to achieve this capability, specifically for operations beyond the Line-of-Sight, would be to equip air vehicles with a vision-based system using cameras to monitor the surrounding air space and to classify other air vehicles flying in close proximity. This paper presents an image-based application for the supervised classification of air vehicles.
2015-09-15
Technical Paper
2015-01-2479
Stefan Benischke, Frank Thielecke
Abstract The continuous need for improved high lift performance motivates the evaluation of innovative high lift systems. Single flap drive systems are possible solutions to implement novel functionalities for aerodynamic performance optimization. The previously mechanical coupling needs to be replaced by approved equivalent means. This directly results in high demands on control and monitoring of the multiple single drive systems in order to preserve a safe operation. In the context of the national German research project SysTAvio, strategies for a new concept of a multifunctional high lift system are investigated and presented in this paper. The conceptual system comprises four single flap surfaces, each driven by a local transmission system and powered by a local power control unit. This architecture requires an innovative control strategy for a safe operation of a single drive system as well as synchronous movement of multiple systems.
2015-09-15
Technical Paper
2015-01-2481
Rudolf Neydorf
Abstract The solution of the both synthesis and implementation problems of high-rapid rates control laws is extremely important for the development of automatic control systems of the aircraft. This is due to the high speed of such vehicles. Along with this, it is imperative that control laws provide that system is asymptotically stable, as the basis for the reliability of their controlled motion. Another important objective of the method of synthesis of control laws for aircraft is compulsory compliance with strict limitations on the values of control inputs at the actuation devices. It is equally important that the control laws provides limitations on the state variables of aircraft, such as velocity, acceleration, etc. Pontryagin's maximum principle is aimed at solving such a time-optimal problem with the limited command variable.
2015-09-15
Technical Paper
2015-01-2482
Riko Bornholdt, Tobias Kreitz, Frank Thielecke
Abstract For the shift to more-electric aircraft systems, the system specific design paradigm has to be dissolved and the allocation of functions has to be reconsidered. Including more degrees of freedom within the architecture design process for aircraft systems could lead to beneficial architecture concepts. However, new methods for conceptual systems design are required, to cope with the significantly increasing number of potential architecture variations to be evaluated. Within this paper, the GENESYS methodology enabling the design and evaluation of numerous architecture variations will proposed. The methodology consists of several modules, each dedicated to a specific process step of conceptual aircraft system design. Initially, a method for the design-independent analysis of the aircraft level functions and the identification of requirements for the aircraft systems will be illustrated.
2015-09-15
Technical Paper
2015-01-2522
Mirko Jakovljevic, Jan Radke, Perry Rucker
Abstract VPX, as a switched fabric, supports the design of advanced integrated systems using technologies such as deterministic Ethernet. Deterministic Ethernet can be used in backplane and backbone applications. In cases where functional interrelationships and Ethernet network bandwidth sharing is deterministic and all logical links among critical function have configurable quality of service with guaranteed timing, the complexity challenges in design of advanced integrated architectures can be much simpler to handle and mitigate. VPX switches in 3/6U format with ARINC664 and SAE AS6802 services enable deterministic integration of many critical functions hosted on common embedded computing and networking resources. Both ARINC664 (asynchronous real-time) and SAE AS6802 (synchronous hard real-time), as Layer 2 enhancements, do not affect existing Ethernet services.
2015-09-15
Technical Paper
2015-01-2533
Philippe Coni, Frederic Merino, Frederic Renaud
Abstract Projected capacitive touchscreen (PCAP) became popular thanks to the introduction of the Apple iPhone, iPad and iPod. Electrical field generated for touch detection is known to be impaired by external fields, for example Cold Cathode Fluorescent Lamp, USB charger or AMLCD driving. Commercial product shall live with this issue, but the high intensity radiated field required for avionics application is several orders of magnitude higher than required for commercial product. In such an environment, standard touchscreens could have hazardous behavior. Thanks to the unique 20 years' experience on projected capacitive technology (Aircraft fighter), we designed a new projected capacitive touchscreen, based on a ruggedized touch controller and dedicated ASIC, able to operate in extreme electromagnetic environment.
2015-09-15
Technical Paper
2015-01-2541
Alejandro Murrieta-Mendoza, Ruxandra Botez
Abstract This paper describes an optimization algorithm that provides an economical Vertical Navigation profile plan by finding the combinations of climb, cruise and descent speeds, as well as the altitudes for an aircraft to minimize flight costs. The computational algorithm profits from a space search reduction algorithm to reduce the initial number of speed and altitude combinations. Additional search space reductions were performed with the implementation of the branch and cut algorithm. A bounding function that correctly estimates the flight cost considering step climbs was developed to reduce the number of calculations. The full flight fuel burn cost was obtained using a performance database- based method. The fuel flight cost was computed using the cost index. This algorithm used a performance database instead of equations of motion to compute fuel burn. This database was developed and validated by our industrial partner using real flight experimental data.
2015-09-15
Technical Paper
2015-01-2523
Pierre Coustal, Franck Tailliez
Abstract In the Integrated Modular Avionics (IMA) domain, THALES developed a high performance communication network named SAEN (Self Adaptive Embedded Network). SAEN is a switchless network solution, fully embedded in a single Network Component Interface (NCI), aimed to interconnect easily several modules of a system, in any mesh network topology. Once each module is equipped with its network component, just connect them together to realize the wanted topology and switch ‘on’ the modules power supplies. At power-on, all the nodes of the network aggregate to form a complete global and coherent network, autonomously managing its configuration and the optimal static routing between any emitter and receiver. The constituted network is deterministic, autonomous, self-discovering, and auto-adapting to the network variations and guarantees an optimal routing in any situation of the graph, as long as a path exists.
2015-09-15
Technical Paper
2015-01-2527
Mirko Jakovljevic, Jan Radke
Abstract Integrated modular architectures and IMA reduce the physical complexity of electronic architecture by integrating many functions on common embedded resources. As the reduction of physical complexity means that the embedded resources are shared by many functions, the logical complexity of system configuration, functional alignment and resource sharing increases significantly. Modern integrated embedded platforms are designed for parameter-based architecture design and integration. IMA is not only a set of platform components, networking and computing devices and configurable middleware and platform abstraction layers. Integrated Architectures and IMA require mature design and verification tools, and a well-defined design and integration methodology are required to avoid expensive and error-prone manual analyses and configuration tasks. Therefore, integrated architectures cannot be separated from design methodologies and processes.
2015-09-15
Technical Paper
2015-01-2558
Jörg Brauer, Markus Dahlweid, Jan Peleska
Abstract Software developed according to DO-178C Level A has to undergo extremely rigorous structural coverage analysis to ensure that the code has been adequately exercised during requirements-based testing. The goal of structural coverage analysis is either to show that the requirements-based tests are adequate, or to provide analysis data, which leads to a refinement of the tests. This paper focuses on two particular issues of structural coverage analysis, namely source-code-to-object-code traceability analysis and data coupling and control coupling analysis, both of which have been challenging in the past due to little tool support. We present details of two tools: the RT-Tester Source-Code-To-Object-Code Traceability Analyzer (RTT-STO) and the RT-Tester Data & Control Coupling Analyzer (RTT-DCC), which we have developed for the low-level verification of an Airbus avionic control system, and discuss our practical experiences with tool-supported structural coverage analysis.
2015-09-15
Technical Paper
2015-01-2458
Giuseppe Sirigu, Manuela Battipede, Piero Gili, Mario Cassaro
Abstract The future revolution of the air traffic system imposes the development of a new class of Flight Management Systems (FMS), capable of providing the aircraft with real-time reference flight parameters, necessary to fly the aircraft through a predefined sequence of waypoints, while minimizing fuel consumption, noise and pollution emissions. The main goal is to guarantee safety operations while reducing the aircraft environmental impact, according to the main international research programs. This policy is expected to affect also the Unmanned Aerial Systems (UASs), as soon as they will be allowed to fly beyond the restricted portions of the aerospace where they are currently confined. In the future, in fact, UASs are expected to fly within the whole civilian airspace, under the same requirements deriving from the adoption of the Performance Based Navigation (PBN).
2015-09-15
Technical Paper
2015-01-2478
Tobias Kreitz, Riko Bornholdt, Matthias Krings, Karsten Henning, Frank Thielecke
Abstract 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.
2015-09-15
Technical Paper
2015-01-2554
Kevin Landry, Jean-François Boland, Guy Bois
Abstract The amount of functionalities in modern aircrafts is increasing to satisfy performance, safety and economic benefits. Therefore, the communication needs of avionic systems are growing. Furthermore, the portability and reusability of applications are current challenges of the aerospace industry. The use of the Data Distribution Service (DDS) middleware technology would reduce the complexity of communications and ease the portability and reusability of applications with its standardised interface. Few previous works used a DDS middleware within the aerospace industry and those didn't take into account the impact of this technology on the applications performances. Therefore, this paper presents an impact evaluation of using a DDS middleware on the performances of avionic applications.
2015-09-15
Technical Paper
2015-01-2528
Srikanth Gururajan
Abstract In recent years, there has been an increase in the use of Unmanned Aerial Systems (UAS) in the civilian sector for various purposes. As these platforms are constrained in terms of payload and capacity, they are typically equipped with a minimal sensor suite and the use of redundant sensors is uncommon. This research effort describes the design and simulation of a Neural Network (NN) based fault tolerant flight control approach for sensor and actuator failures, implemented on a parallel and distributed computational architecture. The inter process communication is implemented using BSD sockets and Message Passing Interface (MPI). For the purpose of the sensor failure detection, identification and accommodation (SFDIA) task, it is assumed that the pitch, roll and yaw rate gyros onboard the aircraft are without physical redundancy.
2015-09-15
Technical Paper
2015-01-2539
Alessandro Gardi, Roberto Sabatini, Subramanian Ramasamy, Matthew Marino, Trevor Kistan
Abstract As part of the current initiatives aimed at enhancing safety, efficiency and environmental sustainability of aviation, a significant improvement in the efficiency of aircraft operations is currently pursued. Innovative Communication, Navigation, Surveillance and Air Traffic Management (CNS/ATM) technologies and operational concepts are being developed to achieve the ambitious goals for efficiency and environmental sustainability set by national and international aviation organizations. These technological and operational innovations will be ultimately enabled by the introduction of novel CNS/ATM and Avionics (CNS+A) systems, featuring higher levels of automation. A core feature of such systems consists in the real-time multi-objective optimization of flight trajectories, incorporating all the operational, economic and environmental aspects of the aircraft mission.
2015-09-15
Technical Paper
2015-01-2537
Sylvain Hourlier
Abstract The efficiency of the glass cockpit paradigm has faded away with the densification of the aeronautical environment. Today's problem lies with “non-defective aircraft” monitored by “perfectly trained crews” still involved in fatal accidents. One explanation is, at crew level, that we have reached a system complexity that, while acceptable in normal conditions, is hardly compatible with human cognitive abilities in degraded conditions. The current mitigation of such risk still relies on the enforcement through intensive training of an ability to manage extremely rare (off-normal) situations. These are explained by the potential combination of failures of highly complex systems with variable environment & with variable humans.
2015-09-15
Technical Paper
2015-01-2544
Subramanian Ramasamy, Roberto Sabatini
Abstract Avionic system developers are currently working on innovative technologies that are required in view of the rapid expansion of global air transport and growing concerns for environmental sustainability of aviation sector. Novel Communication, Navigation and Surveillance (CNS) system designs are being developed in the CNS/Air Traffic Management (CNS/ATM) and Avionics (CNS+A) context for mission-and safety-critical applications. The introduction of dedicated software modules in Next Generation Flight Management Systems (NG-FMS), which are the primary providers of automated navigation and guidance services in manned aircraft and Remotely-Piloted Aircraft Systems (RPAS), has the potential to enable the significant advances brought in by time and trajectory based operations. High-integrity, high-reliability and all-weather services are required in the context of four dimensional Trajectory Based Operations / Intent Based Operations (TBO/IBO).
2015-09-15
Technical Paper
2015-01-2542
Alejandro Murrieta-Mendoza, Ruxandra Mihaela Botez, Roberto S Félix Patrón
Abstract Flight trajectory optimization algorithms reduce flight cost and fuel consumption, thereby reducing the polluting emissions released to the atmosphere. Ground teams and avionics equipment such as the Flight Management System evaluate different routes to minimize flight costs. The optimal trajectory represents the flight plan given to the crew. The resulting flight plan contains waypoints and weather information such as the wind speed and direction and the temperature for each waypoint. The flight plan is normally introduced manually into the Flight Management System. In this paper, genetic algorithms were applied to the waypoints available in a flight plan to find the altitudes that minimize total fuel consumption, taking into account the cruise-climb and cruise-descent steps' costs. The genetic algorithms emulate the evolution process through a predefined number of generations.
2015-09-15
Technical Paper
2015-01-2556
Thomas Rousselin, Guillaume Hubert, Didier Regis, Marc Gatti
Abstract The changes brought by the increasing integration density and the new technological trends have pushed the reliability at its limit. Safety analysis for critical system such as embedded electronics for avionics systems needs to take into account these changes. In this paper, we present the consequences on the deep sub-micron (DSM) CMOS devices concerning their single event effect (SEE) sensitivity. We also propose a new modeling method in order to address these issues.
2015-09-15
Technical Paper
2015-01-2413
Anngwo Wang, Jonathan Davies, Seth Gitnes, Lotfi El-Bayoumy
Abstract The instantaneous efficiency of an epicyclic geared rotary actuator is an important factor in sizing flight control systems where compound epicyclic gear trains are typically used. The efficiency variation can be smooth or fluctuating depending on the combination and timing of the teeth of ring gears, planet gears and sun gears. In a previous paper [1], the instantaneous efficiency characteristics of actuators with symmetric planets were investigated. The actuator's reacting forces on the planets are symmetric and the overall length of the planet gears will not affect the efficiency. In this paper, a cantilever actuator with asymmetric planet gears is studied. The length and location of the reaction forces on the planet gears are key factors in the efficiency calculation. Theoretical derivation is presented and test results are compared.
2015-09-15
Technical Paper
2015-01-2535
Steven Donald Ellersick, Bill Reisenauer, Mickey Jacobson, Newel Stephens
Abstract The past twenty years have seen tremendous changes in the Avionics display and flight deck lighting due to the application of solid-state LED (light emitting diode) light sources and LCDs (liquid crystal displays). These advances significantly benefit the customer and pilot users when integrated correctly. This paper discusses recommended practices and guidance given in SAE ARP 4103 for modern Avionics flight deck lighting systems to satisfy the end user and obtain certification. SAE ARP 4103 Flight Deck Lighting for Commercial Transport Aircraft has recently been revised to keep up with the Avionics state-of-the-art and add clarification where needed. ARP 4103 contains recommended Avionics flight deck lighting design and performance criteria to ensure prompt and accurate readability and visibility, color identification and discrimination of needed information under all expected ambient lighting and electrical power conditions. For additional details, see the actual ARP 4103.
Viewing 1 to 30 of 976