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Viewing 1 to 30 of 1936
2015-09-20
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2015-09-15
Technical Paper
2015-01-2530
Pierre Dissaux
The Architecture Analysis and Design Language (AADL) standard defines a default runtime semantic for software intensive real time systems. This includes support for multi tasking, network distributed architectures and Time and Space Partitioning systems (TSP). The core definition of the language is extended by the Behaviour Annex that enables a more precise specification of the application real-time behaviour. This allows for the definition of functional pseudo-code for AADL threads and subprograms. It becomes thus possible to describe for instance critical sections or conditional computation depending on input port values. Such a consistent behavioural model can be used for various performance analyses like scheduling and simulation in the early phases of the software development process of real-time critical systems.
2015-09-15
Technical Paper
2015-01-2471
Alessandro Ceruti, Simone Curatolo, Alessandro Bevilacqua, Piergiovanni Marzocca
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
2015-01-2413
Anngwo Wang, Jonathan Davies, Seth Gitnes, Lotfi El-Bayoumy
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.
2015-09-15
Technical Paper
2015-01-2474
Christopher W. Lum, Alexander Summers, Brian Carpenter, Angel Rodriguez, Matthew Dunbabin
In many parts of the world, uncontrolled fires in sparsely populated areas are a major concern. These small fires can quickly grow to large and destructive conflagrations in short time spans. The damage caused by these wildfires are often a function of the time elapsed between detection of the fire and deployment of firefighting resources. Fires detected relatively quickly can be more easily contained than fires that have been allowed to grow before taking corrective action. Detecting these fires has traditionally been a job for trained humans on the ground or in the air. In many cases, these manned solutions are simply not able to survey the amount of area necessary to maintain sufficient vigilance and coverage. This paper investigates the use of unmanned aerial systems (UAS) for automated wildfire detection. The proposed system uses low-cost, consumer-grade electronics and sensors combined with various airframes to create a system suitable for automatic detection of wildfires.
2015-09-15
Technical Paper
2015-01-2529
Mahendra Muli, Vivek Moudgal, Jace Allen
Aerospace and Defense industry is currently challenged in multiple ways – cost cutting and sequestration on the defense side, and spurt of growth on the commercial aviation side of business. While these are opposing trends, both will impose a severe challenge to the management of product development process for both OEMs and Suppliers. The challenge becomes severe as the innovation expectations become rapid with increase in embedded software content in avionics and advent of new category of autonomous ground, marine, and air systems. Clearly, the industry need is to have a product development process that allows for reducing costs, while increasing embedded software quality and thereby product quality even in an iterative development process.
2015-09-15
Technical Paper
2015-01-2482
Riko Bornholdt, Tobias Kreitz, Frank Thielecke
The trend towards all-electric aircrafts leads to an increased complexity and extent of the electrical power system and its interactions with adjacent systems. These interactions need to be analyzed in detail, to identify safety bottlenecks as well as beneficial synergies. Consequently, the system specific design paradigm has to be dissolved, to utilize the full potential of more-electric applications. In this regard, an approach to investigate the interactions between the power systems and innovative flight controls of a regional aircraft is pursued at the Hamburg University of Technology. In a first step, flight dynamics analyses were conducted to identify the distinct requirements for the flight controls. The design of electrically actuated flight controls and an electrical power system architecture for the regional aircraft shall be presented in the intended paper.
2015-09-15
Technical Paper
2015-01-2479
Stefan Benischke, Frank Thielecke
Future high lift system configurations without mechanical interconnection of the flaps would allow for novel functionalities. Through a differential setting of the individual flap surfaces, an optimization of aerodynamic performance can be achieved. Single flap drive systems are possible solutions to implement this kind of multifunctional high lift systems. 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. Control strategies for a new concept of a multifunctional high lift system are presented in this paper. The presented concept comprises four single flap surfaces, each driven by a local transmission system 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
Synthesis of Time Quasi-Optimal Asymptotically Stable Control Laws Rudolf Neydorf 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
2015-01-2478
Tobias Kreitz, Riko Bornholdt, Matthias Krings, Karsten Henning, Frank Thielecke
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 i.a. with respect to system safety requirements. In this context, flight dynamic characteristics and handling qualities of the fully operational as well as several degraded system states of each topology have to be evaluated and checked against common specifications. Here, a model-based verification of the requirements is favorable, resulting in a rapid reduction of the design space.
2015-09-15
Technical Paper
2015-01-2458
Giuseppe Sirigu, Manuela Battipede, Piero Gili, Mario Cassaro
The revolution of the air traffic system, started with the introduction of the 4-Dimentional Trajectories (4DTs), imposes the development of new class of Flight Management Systems (FMS), capable of solving a constrained non-linear optimization problem to provide 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 through the aircraft separation and sequencing while reducing the aircraft environmental impact, according to the international research programs like SESAR, Clean Sky and NextGen. The actual challenge is to meet these requirements with minimum modifications of the avionic systems. This goal is achieved by developing a FMS that uses the existing aircraft autopilot suite in order to follow the calculated reference trajectory.
2015-09-15
Technical Paper
2015-01-2528
Srikanth Gururajan
In recent years, there has been an increase in the use of Unmanned Aerial Systems (UAS) in both civilian as well as military sectors for a wide range of applications including aerial reconnaissance of military targets, monitoring traffic, geological mapping, search and rescue among others. Typically with the use of UAS, there is a premium on total weight and cost, in order to maximize their payload potential and as a consequence, the use of redundant sensors is uncommon. In addition, UAS have gained wide acceptance as the platforms of choice for implementing high risk/high reward flight control algorithms, especially addressing sensor and actuator failure scenarios, thanks to the low logistical burden. This research effort describes the design and simulation of a distributed Neural Network (NN) based fault tolerant flight control scheme for sensor and actuator failures and the interface of the scheme within a simulation/visualization environment.
2015-09-15
Technical Paper
2015-01-2472
Tom Owen
SUAV is a 4 year investigation with the aim of designing, manufacturing and integrating a 3kg Solid Oxide Fuel Cell (SOFC) into an existing 10kg fixed wing UAV which is already in commercial service. The project comprises of a collaboration of 1o partners, each having a commercial or scientific interest in the design. Each partner provides specialist knowledge at system component level. This paper will present an overview of the problem space and present the methods used to generate the system level requirements. A top level overview will then be given of the resultant system design. This paper will also discuss some of the platform performance benefits and drawbacks of fuel cell operation.
2015-09-15
Technical Paper
2015-01-2523
Pierre Coustal, Franck Tailliez
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 easily interconnect 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. A power-on, all the nodes of the network aggregate them to form a whole global and coherent network, managing autonomously its configuration and the optimal static routing between any emitter and receiver. The constituted network is deterministic, autonomous, self-discovery, auto-adaptive 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
2015-01-2535
Steven Donald Ellersick, Bill Reisenauer, Mickey Jacobson, Newel Stephens
The past twenty years have seen tremendous change 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 user when integrated correctly. This paper discusses recommended practice 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 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.
2015-09-15
Technical Paper
2015-01-2554
Kevin Landry, Jean-François Boland, Guy Bois
Modern aircrafts must include an increasingly amount of functionalities to satisfy the needs of the customers. Therefore, the communication needs of avionic systems are growing. Furthermore, the portability and reusability of applications are current challenges of the avionic 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 avionic 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. To do so, an automatic flight control system (AFCS) was modeled with Simulink to control a Boeing 747-400 simulated within the X-Plane flight simulator.
2015-09-15
Technical Paper
2015-01-2522
Mirko Jakovljevic, Jan Radke, Perry Rucker
In this paper, we will describe basic principles for design of open IMA architectures using VPX standard, and describe based on space avionics architetcure, how those components can be used for definition of open VPX-based architectures for IMA and integrated systems. VPX, as a switched fabric, supports the design of advanced integrated systems using technologies such as deterministic Ethernet, which 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. This enables design of truly open and flexible modular embedded systems, which can host hard real-time, real-time, and soft functions at lower system lifecycle costs.
2015-09-15
Technical Paper
2015-01-2527
Mirko Jakovljevic, Jan Radke
In this paper we will provide an overview o tools and methods required for design and verification fo complex AFDX/TTEthenret networks. One of key aspects is the toolchain discussion and verification of timing guarantees and configuration.
2015-09-15
Technical Paper
2015-01-2533
Philippe Coni, Frederic Merino, Frederic Renaud
Projected capacitive touchscreen (PCT) 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 RAFALE), 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
2015-01-2537
Sylvain Hourlier
The efficiency of the glass cockpit paradigm has faded away with the evolution of the aeronautical environment (traffic increase & permanence of service). Today's problem lies with "non-defective aircraft" monitored by "perfectly trained crews" still involved in fatal accidents. One explanation is, at the 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
2015-01-2542
Alejandro Murrieta-Mendoza, Ruxandra Mihaela Botez, Roberto S Félix Patrón
Flight trajectory optimization algorithms reduce flight cost regardless of the aircraft technologies. Besides flight cost reduction, diminishing fossil fuel consumption leads to reducing polluting emissions. Ground teams and avionic equipment such as the flight management system seek for the routes that minimize the flight cost. The flight plan also contains the trajectory information in the form of waypoints to follow. This plan is provided to the pilot and is introduced into the flight management system. The flight plan contains as well weather information such as wind and temperature. In this paper, genetic algorithms were applied to the waypoints available in the flight plan to find the combination of altitudes that minimize the flight time and fuel burned. In the literature trajectories are normally taken from radar date, or the geodesic route between two points amongst others. Published waypoints are seldom used.
2015-09-15
Technical Paper
2015-01-2558
Jörg Brauer, Markus Dahlweid, Jan Peleska
The DO-178C requires data and control coupling (DC/CC) analysis to be performed as part of the validation activities. Here, “data coupling” between software components is defined as the dependence of a component on data that is not exclusively under the control of that component. Likewise, “control coupling” is defined as the degree by which one component influences the execution of another component. The intent of DC/CC analysis is then to provide assurance of the correctness of the interactions between different components, which can for example be achieved by integration tests. Unfortunately, DC/CC analysis has often been misunderstood as a review activity to ensure that the code correctly implements the design, whilst its de-facto purpose is to validate the verification activities.
2015-09-15
Technical Paper
2015-01-2539
Alessandro Gardi, Roberto Sabatini, Subramanian Ramasamy, Matthew Marino, Trevor Kistan
The potential benefits offered by advanced aircraft navigation technologies will be ultimately exploited only through the dynamic allocation of resources in a highly automated airspace. In this respect, the deployment of Four Dimensional Trajectory (4DT) functionalities in an Intent Based Operations (IBO) environment is envisaged as a fundamental enabler of future Air Traffic Management (ATM) services. The 4DT-IBO, in turn, are requiring the introduction of novel Communications, Navigation and Surveillance and ATM (CNS/ATM) systems, enabling the migration from traditional voice communications to data-driven negotiation and validation functions. A novel ground-based 4DT Planning, Negotiation and Validation (4-PNV) system is being developed in conjunction with Next Generation Flight Management Systems (NG-FMS) and Mission Management Systems (NG-MMS) for integration into the future air traffic scenario.
2015-09-15
Technical Paper
2015-01-2475
Francesco Cappello, Roberto Sabatini, Subramanian Ramasamy
Accurate and robust tracking of objects is of growing interest among the computer vision scientific communities. The ability of a vision system to detect and track the objects, and accurately predict their future trajectory is critical in the context of mission- and safety-critical applications. Remotely Piloted Aircraft Systems (RPAS) are not currently equipped to routinely access all classes of airspace and thus providing the pathway to coexist seamlessly with manned aircraft. Such capabilities can be achieved by incorporating both cooperative and non-cooperative Detect-And-Avoid (DAA) functions, as well an providing enhanced communications, navigation and surveillance (CNS) services. DAA is highly dependent on the performance of CNS systems, specifically for Tracking, Deciding and Avoidance (TDA) tasks.
2015-09-15
Technical Paper
2015-01-2544
Subramanian Ramasamy, Roberto Sabatini
Novel Communication, Navigation, Surveillance/Air Traffic Management (CNS/ATM) systems are currently developed, in line with the roadmap defined by large-scale research initiatives including Single European Sky ATM Research (SESAR) in Europe, Next Generation Air Transportation System (NextGen) in US, and other programmes worldwide. The demand for improved safety, integrity and efficiency due to the rapid expansion of global air transport and the growing concern for environmental sustainability issues poses significant challenges on the development of CNS/ATM and Avionics (CNS+A) systems. High-integrity and high-reliability mission- and safety-critical ATM and avionic systems are therefore required in the context of Four Dimensional (4D) Trajectory Based Operations / Intent Based Operations (TBO/IBO).
2015-09-15
Technical Paper
2015-01-2541
Alejandro Murrieta-Mendoza, Ruxandra Botez
Flight trajectory optimization has been identified as a way to reduce flight costs and to diminish polluting emissions to the atmosphere due to fuel powered engines. The Flight management system is a device that among its functions is in charge of flight optimization. This paper presents an optimization algorithm that solved the Vertical Navigation problem by providing the combinations of climb, cruise and descent speeds along with altitudes the aircraft should follow to minimize the flight cost. Due to flight management system computation power limitations, this algorithm aims to find the solution with just little calculations. The developed algorithm took advantage of a space search reduction algorithm to reduce the initial number of speed/altitude combinations available since the first iteration. Additional search space reductions were performed with the implementation of the branch and cut algorithm.
2015-09-15
Technical Paper
2015-01-2556
Thomas Rousselin, Guillaume Hubert, Didier Regis, Marc Gatti
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
2015-01-2440
Robert Moehle, Jason Clauss
From the dawn of commercial air travel until 2001, labor costs loomed as the greatest expense in commercial aviation. Though fuel costs have since taken the top spot, labor costs remain a pressing area of concern in the airline industry. Airlines have long sought to reduce the burden of labor to improve the businesses’ bottom line. One of their most frequent appeals has been to allow a single flight crew member to operate the aircraft. Safety concerns represent the dominant barrier to single-pilot Part 121 operations. The FAA and Congress consistently demonstrate a bias toward conservatism in their regulation of airlines and commercial aircraft. Under-educated on the true failure rates, bureaucrats and the general public fall prey to isolated news stories about pilots becoming ill or falling asleep in the flight deck. Yet, in an alarming spate of recent airline accidents, the presence of multiple crewmembers did nothing to prevent, and actually may have contributed to, the crash.
2015-09-15
Technical Paper
2015-01-2531
Lin Bao, Guy Bois, Jean-François Boland, Julien Savard
The Integrated Modular Avionics (IMA) architecture has been a crucial concern for the aerospace industry in developing more complex systems, while seeking to reduce space, weight and power (SWaP), as well as development, certification and production time. From a software perspective, that objective pushes developers to migrate toward a safety critical space and time partitioning environment, usually compliant with the ARINC 653 standard which specifies a series of robust partitioning mechanisms and services that an operating system (OS) must satisfy to guarantee such isolation. The research work presented in this paper aims to propose to the aerospace industry a set of time-effective and cost-effective solutions for the integration and functional validation of IMA systems. The proposed methodology mainly focuses on a novel model-based engineering design flow (MBE). In the first step of the design flow, the modeling language AADL is used to describe the IMA architecture.
2015-09-15
Technical Paper
2015-01-2532
Sylvain Hourlier, Sandra Guérard, Jean Luc BAROU, Xavier Servantie
As touch screens are everywhere in the consumer market Thales has launched in depth evaluations on their introduction in the cockpit. One of the challenges is to verify its compatibility with in flight use under turbulence conditions, including light, moderate and severe. In flight accelerometer collections were performed to provide us with a baseline for choosing between possible simulation solutions. Thales recognized early on the need for such a tool as it would enable us to define recommendations for our HMI designs. The objectives were first to validate specific complex touch/gestures using all the potential of touch interactions for novel cockpit Human Machine Interfaces and second to look into the various physical anchoring solutions capable of facilitating touch screens interactions in aeronautical turbulent environments. Given the 6 axis accelerometer profiles that were collected, a number of potential candidate simulation platforms were selected.
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