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Technical Paper
2014-09-16
Srikanth Gururajan, Mario Luca Fravolini, Matthew Rhudy, Antonio Moschitta, Marcello Napolitano
Recent catastrophic air crashes have shown that physical redundancy is not a foolproof option for failures on Air Data Systems (ADS) on an aircraft providing airspeed measurements. Since all the redundant sensors are subjected to the same environmental conditions in flight, any failure on one of the sensors is likely to occur on the other sensors under certain conditions such as extreme weather; this class of failure is known in the literature as “common mode” failure. In this paper, different approaches to the problem of detection, identification and accommodation of failures on the Air Data System (ADS) of an aircraft are evaluated. This task can be divided into component tasks of equal criticality as Sensor Failure Detection and Identification (SFDI) and Sensor Failure Accommodation (SFA). Data from flight test experiments conducted using the WVU YF-22 unmanned research aircraft are used. This research platform was designed, manufactured, instrumented, and flight tested by researchers at the Flight Control Systems Laboratory (FCSL) at West Virginia University (WVU).
Technical Paper
2014-09-16
Rodrigo Felix, John Economou, Kevin Knowles
Upon their arrival, Unmanned Autonomous Systems (UAS) brought with them many benefits for those involved in a military campaign. They can use such systems to reconnoitre dangerous areas, provide 24-hr aerial security surveillance for force protection purposes or even attack enemy targets all the while avoiding friendly human losses in the process. Unfortunately, these platforms also carry the inherent risk of being built on inherently vulnerable cybernetic systems. From software which can be tampered with to either steal data, damage or even outright steal the aircraft, to the data networks used for communications which can be jammed or even eavesdropped on to gain access to sensible information. All this has the potential to turn the benefits of UAS into liabilities and although the last decade has seen great advances in the development of protection and countermeasures against the described threats and beyond the risk still endures. With this in mind the present work will describe a monitoring system whose purpose is to monitor UAS mission profile implementation at both high level mission execution and at lower level software code operation to tackle the specific threats of malicious code and possible spurious commands received over the vehicle’s data links.
Technical Paper
2014-09-16
Zachary A. Collier, Steve Walters, Dan DiMase, Jeffrey M. Keisler, Igor Linkov
Counterfeit electronic components entering into critical infrastructure and applications through the global supply chain threaten the economy and national security. In response to the growing threat from counterfeits, the Society of Automotive Engineers G-19 Committee is developing AS6171. This aerospace standard is focused on testing facilities with a goal of standardizing the process of counterfeit detection. An integral part of the standard is a semi-quantitative risk assessment method. This method assigns risk scores to electronic components based on a number of relevant criteria, and places the components into one of five risk tier levels corresponding to an appropriate level of laboratory testing to ensure the authenticity of the component. In this way, the methodology aims at standardizing the risk assessment process and bases the identified risk as guidance for commensurate testing protocols. This paper outlines the risk assessment method contained within AS6171 and briefly explores other complementary efforts and research gaps within the G-19 and electronics community.
Technical Paper
2014-09-16
Ephraim Suhir, Alain Bensoussan
The attributes of and challenges in the recently suggested probabilistic design for reliability (PDfR) concept, and the role of its major constituents - failure oriented accelerated testing (FOAT) and physically meaningful predictive modeling (PM) - are addressed, advanced and discussed. The emphasis is on the application of the powerful and flexible Boltzmann-Arrhenius-Zhurkov (BAZ) model, and particularly on its multi-parametric aspect. The model can be effectively used to analyze and design optoelectronic (OE) devices and systems with the predicted, quantified, assured, and, if appropriate and cost-effective, even maintained probability of failure in the field. The numerical example is carried out for an OE system subjected to the combined action of the ionizing radiation and elevated voltage as the major stimuli (stressors). The measured leakage current is used as a suitable characteristic of the degree of degradation. It is concluded that the suggested methodology can be accepted as an effective means for the evaluation of the operational reliability of the aerospace electronics and OE systems and that the next generation of qualification testing (QT) specifications and best practices for such systems could be viewed and conducted as a “quasi-FOAT,” a sort of an “initial stage of FOAT” that adequately replicates the initial non-destructive segment of the previously conducted comprehensive “full-scale” FOAT.
Technical Paper
2014-09-16
Javier Gazzarri, Nishant Shrivastava, Robyn Jackey, Craig Borghesani
Battery management system design is a complex problem that requires sophisticated models of the battery cell that mimic their electrochemical behavior under a variety of operating conditions. Equivalent circuits offer an adequate balance between fidelity and simulation speed, their parameters reflect direct experimental observations, and they are largely scalable. Scalability is particularly important at the real time simulation stage, where a model of the battery pack runs on a real time simulator that is physically connected to the peripheral hardware in charge of monitoring and control. With modern battery systems comprising hundreds of cells, it is important to count on a modeling and simulation approach that is capable of handling numerous simultaneous instances of the basic unit cell and still be real time capable. In previous publications we presented a technique for the creation of a battery cell model that contains the electrochemical fingerprints of a battery cell based on equivalent circuit model fitting to experimental data.
Technical Paper
2014-09-16
Prashant Vadgaonkar, Ullas Janardhan, Adishesha Sivaramasastry
Performance of Avionics systems is dictated by the timely availability and usage of critical health parameters. Various sensors are extensively used to acquire and communicate the desired parameters. In the Present day’s scenario, sensors are configured with wired approach. Number of sensors is growing due to automation, increasing the accuracy of intended Aircraft functions. Sensors are distributed all over the Aircraft and they are connected through wired network for signal processing and communicating. LRU’s which are integrating various sensors also use wired approach for communication. The Key driver for Airline operational cost is fuel. Fuel quantity is a direct function of weight. Weight of cables contributes significantly to the overall weight of the aircraft. Use of wired network approach poses challenges in terms of cable routing, stray capacitances, noise and mechanical structure. This paper describes various merits and demerits of wired sensors and their interface techniques.
Technical Paper
2014-09-16
Kazuki Shibata, Tomo Maedomari, Kenichi Rinoie, Noriko Morioka, Hitoshi Oyori
In aircraft conceptual design, we consider several different configurations and systems so that performance requirement can be satisfied. When choosing many sets of parameters, designers try to make all the objective functions as good as possible, and then determine the best aircraft configuration. In this case, however, the feasibility of this best aircraft configuration is somewhat doubtful because we haven’t considered aircraft secondary power systems which are indispensable for aircraft operation. Therefore we need to include the consideration of aircraft secondary power systems into the conceptual design. Past studies of conceptual designs with aircraft secondary power systems are few compared with those into which detailed analyses of aerodynamics, structural dynamics, flight stability and propulsion have been integrated. One reason might be that detailed data of existing aircraft is difficult to obtain. Second, basic methods which integrate secondary power systems analyses into conceptual design process haven’t been discussed in detail in the literature.
Technical Paper
2014-09-16
Aurelie Beaugency, Marc Gatti, Didier Regis
Since 2000, avionics is facing several changes, mostly driven by technological improvements in the electronics industry and innovation requirements from aircraft manufacturers. First, it has progressively lost its technological leadership over innovation processes in the economy. Second, the explosion of the electronics consumer industry has contributed to shorten even more its technology life cycles, and promoted the use of COTS. Third, the increasing complexities of avionics systems, which integrate more and more functions, have encouraged new players to enter the market. In this context, firms’ ability to quickly face technological changes provides competitive advantage. The aim of this article is to analyze how technological changes can affect the competitive environment of avionics firms. More precisely, we refer to criticality levels as a determinant of the market competitiveness. According to its criticality, each avionic system is ranked from A (highly critical) to E in the DO 178b standard.
Technical Paper
2014-09-16
Massimo Conte, Michele Trancossi
This paper presents the definition of a novel system for autonomous landing and docking, which has been conceived and developed inside the MAAT project, to allow an effective control during autonomous docking of cruiser and feeder in movement. In particular, this paper is a fundamental technological spin off the MAAT project. It is a new instrumental system for governing relative positioning between a movable target and air vehicles, such as helicopters, airships and multi-copters. In particular, a short time to market application relates to helicopter equipment (both manned and unmanned) to ensure autonomous landing capability even in case of reduced visibility. The proposed solution is based on infrared emitters allowing controlling both position and jaws angle. It is in advanced testing phase have concluded a preliminary testing phase using a quadcopter which has landed on a small platform mounted on an unmanned with capability of landing also in movement. The proposed solution is an effective alternative to more sophisticated vision based systems, which ensures higher affordability, higher simplicity and reduced costs.
Technical Paper
2014-09-16
Ralf D. Pechstedt
Recently, there has been an increasing interest in Fiber Optic Sensors (FOS) for aircraft applications. Drivers are general advantages that FOS offer, but that are particularly relevant to aircraft, including weight savings by replacing electrical cables with optical cables, passive and therefore intrinsically safe sensor heads, immunity to Electromagnetic Interference (EMI) and the ability to carry out measurements in harsh environment. The desire to move towards More Electric Aircraft (MEA) or All Electrical Aircraft (AEA) could require the deployment of additional sensors, making weight saving even more important. Further, new opportunities arise in the areas of Structural Health Monitoring (SHM) due to the ease of multiplexing employing Fiber Bragg Gratings (FBG) and the potential to combine operational load monitoring with impact damage detection. Many of the FOS are based on different transducer mechanisms, and hence, have to employ sensor-specific readout systems. However, for ease of maintenance and cost saving purposes, a 'universal interrogator' that can be used with at least a large sub-group of sensors is the preferred option for deployment in aircraft.
Technical Paper
2014-09-16
Thierry Cornilleau, Pierre Linard, Paul Moxon, Christopher Nicholas
UK and French Aerospace industries are currently collaborating, under the Anglo-French Government Memorandum of Understanding, on a programme, named ECOA (European Component Oriented Architecture) which aims to reduce the development and through-life-costs of the increasingly complex software systems within military air platforms. The ECOA programme defines an open real-time software architecture, agreed between the programme partners, that meets these goals. The software architecture is based around a number of key concepts: the use of flexible architectural paradigms which provide event and data distribution, the precise specification of software artefacts, allowing a detailed understanding of functional and non-functional behaviour, a better model of distributed real-time behaviour, the support for Model-Driven Engineering (MDE) and automated code generation to reduce development costs, the ability to support any underlying hardware and software platform ensuring the approach is able to support legacy and new build platforms, and the creation of a market for software artefacts, based on an agreed breakdown of mission systems functionality.
Technical Paper
2014-09-16
Shweta Sanjeev, Goutham Selvaraj, Patrick Franks, Kaushik Rajashekara
In a More Electric Aircraft, there is a need to integrate power electronics with the starter generator system. The power electronics operates in the hostile engine environment. This requires use of power devices and passive components that are capable of operating at high temperatures (200-250 C). Wide band gap materials such as Silicon-Carbide (SiC) and Gallium Nitride (GaN) are used as power devices to provide the power conversion at high temperature. In this project, a 50 kVA high temperature bi-directional converter provides the power conversion for starter generator system at 200 C, which can be directly mounted on the engine compartment. The converter is a three phase PWM active rectifier, based on SiC MOSFET. During starter mode, the converter acts as an inverter providing AC voltage to the motor to start the engine During generator mode it functions as an active rectifier converting the AC voltage to 540V DC (+/-270V DC). The DC output of the converter provides power to the platform’s HVDC loads, DC-AC inverter fed AC loads and 28V DC loads.
Technical Paper
2014-09-16
Hitoshi Oyori, Shingo Nakagawa, Hidefumi Saito, Norio Takahashi, Manabu Seta, Noriko Morioka
With the growth of onboard electrification and the constant improvement of ECO standards, aircraft electricity load has maintained a rapid, high growth. The More Electric Architecture for Aircraft and Propulsion (MEAAP) is emerging as a viable solution for improved performance and eco-friendly aircraft operations. This study proposes a conceptual system design of All Electric Aircraft, or AEA, incorporated with electrical management for onboard systems. The authors have discussed the future of aviation with an airliner. The airliner imagines the likelihood of some effective improvements in aviation by More Electric Aircraft concept. The operators, the pilots and the maintenance crews expect improvement of operability, maintainability and fuel saving, while requiring high reliability and safety. System designers struggle to optimize lighter weight, shorter propulsion operating and lower cost as well as these requests. This study proposes three points for optimization of onboard systems, which are environment control system, flight control system, engine control system, landing gear system and electric power system.
Technical Paper
2014-09-16
Manxue Lu
This article attempts to provide a big picture of systems engineering in both philosophy and engineering perspectives, discusses current status and issues, trends of systems engineering development, future directions and challenges, followed by certain examples.
Technical Paper
2014-09-16
Mike Boost
Rechargeable lithium batteries are essentially ubiquitous in our daily lives and in virtually every industry from pocket key fobs to billion dollar space programs, in benign as well as extreme environments. Cell production in 2012 was estimated at 4.4 billion cells and expected to double by 2016. However within civil aviation, lithium batteries are still in the early stages of deployment. The general consensus within the industry is that the use of lithium batteries within civil aviation will increase substantially in the coming years. Within the past decade the use of rechargeable lithium batteries has been certified on several platforms including Airbus, Cessna and Boeing. Airframe manufacturers are highly focused on the potential for the lithium technology to reduce the weight and thus increase range for their aircraft. However, there are numerous considerations within the lithium battery design that must be addressed to achieve optimal safety, more specifically lithium cell determination and electronic design.
Technical Paper
2014-09-16
Prashant Vadgaonkar
Today's digital avionics systems leverages the maximum use of the Embedded COTS to fit the need of small form factor, low power, reduce time to market, reducing development time and efficient use of DO-254 for compliance of product. Without the use of Embedded COTS Hardware the time to market is more, compliance efforts are high and complexity of the design increases dramatically. COTs are very useful for Development Assurance Level C and below, new trend is to use it for Level A and B as well, where we can get enormous benefit on efforts on compliance and time to market. COTS modules are entering in digital avionics systems as COM (Computer On Module)/SOM (System On Module)/SIP (System In Package) with huge advancement in semiconductor and packaging industry. Digital systems like cockpit (Drive for Digital Cockpit), Air data management and Fuel Quantity Gauging and Indicating Systems etc. leveraging the COTS for their redesigns, to invent/evolve new products in digital avionics segment.
Technical Paper
2014-09-16
Vincent Metzger, Douglas Parker, Alain Philippe, Sebastien Claudot
Vanessa Pagot, Douglas Parker, Sébastien Claudot, Alain Philippe, Vincent Metzger Fiber Optics Department Esterline | Connection Technologies | SOURIAU SOURIAU – RD 323 – 72470 CHAMPAGNE - FRANCE vmetzger@souriau.com, +33 601 353 001 (Mobile) dparker@souriau.com, 1-805-312-6039 ABSTRACT: Photonics communication is becoming more dominant in aircraft, shipboard and ground army applications. In the early 90’s, Physical contact connection technology (butt-joint termini) was not foreseen as the most reliable interconnect solution for harsh environment applications subjected to contamination. Nevertheless physical contact technology has proven its high reliability once mated. The technology, with multimode fibers, is now widely used in civilian aircraft in pressured environment for over 20 years with very good return on experience. Today, the FTTx Telecom market is using singlemode fiber over long distance in mass rollouts, leading to passive optical component availability such as splitters which incredibly decreases the cost and increases the reliability level.
Technical Paper
2014-09-16
Noriko Morioka, Hidefumi Saito, Norio Takahashi, Manabu Seta, Hitoshi Oyori
Aircraft system architecture has been continuously changing to improve aircraft efficiency, operability, reliability and safety. Airlines always expect the improvement by any possible approaches, because it is very important for not only safe operation of the aircrafts, environmental consideration such as reduction of CO2 and noise emissions, but also economical reason such as efficient aircraft operation and fuel cost saving. It takes huge effort to change the aircraft system architecture, but along with technology advancement of power electronics, electrification of the system has been gradually introduced into the commercial aircrafts. Conventional aircraft systems have long used a four power drive source: mechanical power, hydraulic power, pneumatic power and electric power. Then concept of More Electric Aircraft (MEA) emerged, replacing mechanical, hydraulic and pneumatic aircraft system power sources with electrical power. With the controllability of electric systems, an MEA system will efficiently and adequately manage energy and power throughout the entire aircraft mission.
Technical Paper
2014-09-16
Evgeni Ganev, William Warr
The more electric architecture (MEA) initiatives continue to be dominating trends in the aerospace industry, as they have for the last two decades. The commercial aircraft business is moving toward no-bleed air environmental control systems (ECS), variable-frequency (VF) and direct current (DC) power distribution buses, and electrical actuation. A typical example is the Boeing 787 platform. The next-generation Boeing and Airbus narrow-body airplanes will most likely use MEA. Some military aircraft already utilize MEA for both primary and secondary flight controls. Substantial progress has recently been made in replacing hydraulic and pneumatic systems with electric ones. These new aerospace and military trends have significantly increased electrical power-generation needs. The overall result has been a significant increase in the challenges to accommodate electrical equipment to the new platforms. This has led to increased operating voltages, and efforts to reduce system losses, weight, and volume.
Book
2014-09-04
William C. Messner
Over the years, the DARPA Challenges in the United States have galvanized interest in autonomous cars, making them a real possibility in the mind of the public, but autonomous and unmanned vehicles have been increasingly employed in many roles on land, in the water, and in the air. Military applications have received a great deal of attention, with weaponized unmanned aircraft (drones) being the most prominent. However, unmanned vehicles with varying degrees of autonomy already have many civilian applications. Some of these are quite familiar (such as the Roomba autonomous vacuum cleaner), while others remain largely out of the public eye (such as autonomous farm equipment). Additional applications and more capable vehicles are rapidly coming to the markets in the years ahead. This book examines a number of economically important areas in which unmanned and autonomous vehicles, also understood here as autonomous technologies, are already used or soon will be. Co-published by SAE International and AUVSI, Autonomous Technologies: Applications That Matter will assist the reader in identifying profitable opportunities and avoiding costly misconceptions with respect to civilian applications of autonomous vehicle technologies as it brings together chapters on how air, water, and ground vehicles are becoming ever more used and appreciated.
Article
2014-07-24
Joysticks are evolving rapidly, improving ergonomics to help improve operator efficiency and increase safety and reliability.
Article
2014-07-24
SAE International recently published J2601 “Fueling Protocols for Light Duty Gaseous Hydrogen Surface Vehicles,” the light-duty hydrogen-fueling protocol that will serve as the baseline for fueling the first generation of hydrogen fuel cell electric vehicle (FCEVs).
Standard
2014-07-24
This SAE Recommended Practice applies to the use of generally available leak detection methods to service motor vehicle passenger compartment air conditioning systems.
WIP Standard
2014-07-23
This specification covers the requirements for radio frequency absorptive component wires and finished cables which function electrically as distributed low-pass filters. Materials and construction details are specified in the applicable specification sheet.
WIP Standard
2014-07-22
SPECIFICATION COVERS A TAPE STYLE DEVICE FOR REPAIRING LARGER SIZE PRIMARY WIRE.
WIP Standard
2014-07-18
The SAE Aerospace Information Report AIR5315 – Generic Open Architecture (GOA) defines “a framework to identify interface classes for applying open systems to the design of a specific hardware/software system.” [sae] JAUS Service (Interface) Definition Language defines an XML schema for the interface definition of services at the Class 4L, or Application Layer, and Class 3L, or System Services Layer, of the Generic Open Architecture stack (See Figure 1 below). The specification of JAUS services shall be defined according to the JAUS Service (Interface) Definition Language document.
Standard
2014-07-17
To provide standard terminology and definitions with regard to ignition systems for spark-ignited internal combustion engines.
Article
2014-07-15
Broader coverage, more features highlight expanding capabilities.
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