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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
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
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
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
Jay Wilhelm, Joseph Close, Wade Huebsch
A Hybrid Projectile (HP) is an aerial vehicle that is ballistically launched, and then transforms into an Unmanned Aerial Vehicle (UAV). It was desirable for a surveillance equipped HP to change its trajectory, and ultimately the point of impact, by departing from its ballistic trajectory after being launched. The exact control surface sizes, location, and actuation along with the control strategies were needed. A method was investigated to utilize deflectable control surfaces in conjunction with a guidance system to maneuver to HP to a desired point of impact while ensuring that the projectile remains statically and dynamically stable. Dual feedback control methods were devised to control heading and pitch using deflectable vertical and horizontal tail surfaces. These control methods were tested and tuned using the Six Degree of Freedom (6DoF) system in Simulink. A cruciform tail section, analyzed in previous work for a 40 mm HP, was utilized so that the HP was statically and dynamically stable.
Technical Paper
2014-09-16
Christopher Ian Hill, Chris Gerada, Paolo Giangrande, Serhiy Bozhko
This paper presents the initial development of a Modelica Library for Electro-Mechanical Actuator system analysis. At present two main system components are described, these are the Power Electronic Converter and Electric Machine, although further components will be added. These models provide the user with the ability to simulate Electric Machine and Power Electronic Converter systems including physical effects, losses and fault conditions. Established modelling programs such as Saber and MATLAB SimPowerSytems are often unable to provide all the aspects required to accurately simulate real systems in an easy to use, flexible manner. Therefore this paper shows how Modelica has been used to create versatile models able to simulate many practical aspects such as Power Electronic Converter losses and Power Electronic Converter faults, Electric Machine losses and Electric Machine faults. Examples are included in order to demonstrate the use of these models within a variety of systems including an Electro-Mechanical Actuator.
Technical Paper
2014-09-16
Didier Regis, Julie Berthon, Marc Gatti
In the last three decades, the integrated circuit industry has followed a steady path of constantly shrinking devices geometries and increased functionality that larger chips provide. These performances and functionality improvements have resulted in a history of new technology generations every two to three years, commonly referred to as .Moore Law. Each new generation has approximately doubled logic circuit density and increased performance by about 40%. Unfortunately these improvements may be reached today at the cost of a loss of reliability and operational lifetime. The increasing integration of embedded systems and the need to support new features requires high-performance and power-efficient processors. This trend pushes toward the use and development of components implemented in advanced CMOS technologies (22nm technology and bellow, the critical feature size of the elementary devices will drop to 5 nm in 2018, for 14 nm technology node). But, critical embedded computing systems have also to fulfill specific safety requirements.
Technical Paper
2014-09-16
Puvan Arumugam, Chris Gerada, Serhiy Bozhko, He Zhang, Weeramundage Fernando, Antonino La Rocca, Stephen Pickering
Aircraft platforms are presently being increasingly modernized due to the global effort towards having a more environmentally responsible transport network. Future aircraft platforms are expected to be more fuel efficient and also simpler to service and maintain. The way towards this goal has been identified as a move towards “more electric” systems by replacement of hydraulic and pneumatic sources of power with electrical counterparts. This can lead to an increased reliance on electrical power for a range of primary functions including actuation, de-icing, cabin air-conditioning and engine start. A more electric power generation system plays a key role in this technology and this paper focuses on the design of a starter/generator for such systems. One of the challenges often encountered in the design of a starter/generator for aero-engines is the need to satisfy the two fundamental functions, namely to energize the engines during start-up and to generate power during normal engine operation.
Technical Paper
2014-09-16
Richard Mourn
The AS-1 Aircraft Systems and Systems Integration Committee is updating AS5643 and related standards and recommendations to accommodate both new develops and lessons learned from programs such as the F-35 Joint Strike Fighter and X-47B UCAS. This paper provides insight into how programs like the F-35, which implements more than 60 AS5643/IEEE-1394 devices per plane, utilize AS5643/IEEE-1394 for a vehicle system network. This unprecedented use of a high speed (491.52Mb/s) serial interface on an aircraft proves the capability of AS5643/1394, and opens the door for higher bandwidth communication between the Control Computer and LRUs. While I/O bandwidth is important, system level deterministic behavior is required for most vehicle system networks and AS5643 coupled with 1394 provides the required deterministic behavior. The paper then explains how 1394’s asynchronous stream capability is used by AS5643 to create a programmable rate-based (time-sliced) protocol that meets the rigorous requirements of advanced aerospace and defense system design all while using COTS silicon.
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
Evan Racine, Zachary Lammers, Street Barnett, John Murphy, Quinn Leland
Electromechanical Actuation System (EMAS) faces some major technological challenges before it could be fully adopted for primary flight control of aircraft, replacing conventional hydraulic actuation system. One of the challenges is the thermal management of EMAS. The working fluid in conventional hydraulic actuation system acts as a coolant while EMAS does not have a readily available heat sink. Another technical challenge facing EMAS for primary flight control is its highly dynamic demand on aircraft electric power system. Its high peak power demand and regenerative power pose a challenge to aircraft electric power generation and distribution system. The purpose of this study is to analyze EMAS’ transient and dynamic electrical and thermal energy flow under a simulated flight envelope and thermal environment. A laboratory test apparatus was set up to evaluate and characterize the energy flow of an EMA subjected to a simulated dynamic flight control surface load and thermal environment.
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
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
Mario Luca Fravolini, Matthew Rhudy, Srikanth Gururajan, Silvia Cascianelli, Marcello Napolitano
A measurement device that is extremely important for Unmanned Aerial Vehicle (UAV) guidance and control purposes is the airspeed sensor. As the parameters of feedback control laws are conventionally scheduled as a function of airspeed, an incorrect reading (e.g. due to a sensor fault) of the Pitot tube could induce an incorrect feedback control action, potentially leading to the loss of control of the UAV. In this paper, building on prior research, the authors compare two models for Pitot tube free airspeed estimation. The analysis was carried out based on multiple flight records is acquired from the West Virginia University YF-22 scale model in order to assess their performance. The objective of this study is to establish the accuracy and reliability of the two airspeed estimation techniques for eventual use as the basis for real-time fault detection of anomalies occurring on the Pitot tube sensor. The first technique is based on an Extended Kalman Filter (EKF) that utilizes the nonlinear kinematic relations between GPS, Inertial Measurement Unit and Air Data System signals.
Technical Paper
2014-09-16
Viacheslav Pshikhopov, Mikhail Medvedev, Victor Krukhmalev, Roman Fedorenko, Boris Gurenko
The paper describes methods for control of docking of two moving stratospheric airships. One of them (cruiser) implements cruising flight at the defined altitude with defined velocity. The other one (feeder) fulfills the mission of chasing the cruiser with following docking operations. Mathematical model of exact airships are used in the work. Instances of structural and algorithmic implementation based on position-trajectory controller. Simulation of docking control were accomplished with proposed methods.
Technical Paper
2014-09-16
Evgeni Ganev, William Warr, Keming Chen
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.
Technical Paper
2014-09-16
Rudolf Neydorf, Sergey Novikov, Nikita Kudinov
Abstract Airship designers research application versions of systems with several ballonets for adjustment of airship roll and/or pitch as a whole. This requires effective automatic status management of each separate ballonet. But multi-ballonet system control issue encounters the absence of industrially measurable variables of each separate ballonet status. Thus status control issue of the system becomes uncertain. The fact requires the issue studying and shaping new scientific and technical solutions. This publication represents research results implying that fairly simple implementation and effective result can be achieved by application of fuzzy control concept. Its application is built on generating the representative quantity of fuzzy production rules. They are based on present set evaluation of known parameters and measured variables. This results in fuzzy but meaningful image of ballonet system status and airship as a whole. Thus achieving fairly good control over multi-ballonet system.
Technical Paper
2014-09-16
Yvan Wilfried Tondji Chendjou, Ruxandra Botez
Measurements of the inertial properties are needed during the design of aircrafts. Furthermore, the knowledge of these measurements is one of the most problems to be solved while studying aircraft rotational motion or even designing aircraft flight control systems. This is the reason why accurate methods for computing aircraft inertial properties have received sustained interest over the years. This paper firstly presents a structural analysis of a drone - the UAS-S4 ETHECATL. Mass, center of gravity position and mass moment of inertia are numerically determined through Raymer and DATCOM statistical-empirical methods, coupled with mechanical calculations. Then, experimental tests are performed using the pendulum method, in order to validate the numerical predictions. When experimentally determining the mass moment of inertia, the bifilar torsion pendulum is used for the moment vertical axis and the simple pendulum for the moment longitudinal and transversal axes determination. A nonlinear dynamic model is developed for rotational motions about the center of gravity of the system under tests.
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.
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.
WIP Standard
2014-08-04
This SAE Aerospace Information Report (AIR) discusses characteristics of data communications for the Joint Architecture for Unmanned Systems (JAUS). This document provides guidance on the aspects of transport media, unmanned systems and the characteristics of JAUS itself that are relevant to the definition of a JAUS transport specification.
WIP Standard
2014-08-04
This document, the JAUS Compliance and Interoperability Policy (ARP6012), recommends an approach to documenting the complete interface of an unmanned system or component in regard to the application of the standard set. While non-SAE AS-4 JAUS documents are referenced in this ARP they are not within the scope of this document and should be viewed as examples only.
WIP Standard
2014-07-31
This SAE Aerospace Standard (AS) defines the testing methods for all aerospace optic cables. The application of the test methods are defined in the slant sheets. Technical, dimensional, mechanical and operating performance requirements for the associated aerospace fiber optic cables are detailed in the applicable specification slant sheet. In the event of conflict between this standard and the slant sheet, the slant sheet shall take precedence.
Standard
2014-07-29
This document defines a set of standard application layer interfaces called JAUS Unmanned Ground Vehicle Services. JAUS Services provide the means for software entities in an unmanned system or system of unmanned systems to communicate and coordinate their activities. The Unmanned Ground Vehicle Services represent the platform-specific capabilities commonly found in UGVs, and augment the Mobilty Service Set [AS6009] which is platform-agnostic. At present ten (10) services are defined in this document.
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.
WIP Standard
2014-07-09
To provide cross reference between test methods across the fiber optics industry.
Book
2014-07-08
This 2014 edition of the Automotive Cockpits and Dashboards Report is the latest in the series of reports by Supplier Business looking at trends and developments in the vehicle cockpit space. Over time we have seen many changes in terms of the design and structure of the main modules and components that go to make up the dashboard and cockpit element of the vehicle’s interior. In particular the increasing level of in-vehicle connectivity has caused interior designers to rethink the layout and content of the dashboard and center console. In this report the main trends and developments are highlighted, with particular reference to examples of the way in which the industry has responded to the challenge. The strongest influence on the vehicle’s cockpit and dashboard continues to be the requirement for in-vehicle connectivity. Consumer demand for seamless connectivity between home, office and vehicle dominates the cockpit’s interior design and structure. The technology required to provide the level of connectivity demanded by users is increasingly complex and, by necessity, has to embrace advanced driver active safety systems (ADAS) and the anticipated development of semi-autonomous and ultimately, fully autonomous vehicles.
Standard
2014-07-07
This ARP provides insights on how to perform a cost benefit analysis (CBA) to determine the return on investment that would result from implementing an integrated Health Management (HM) system on an air vehicle. The word “integrated” refers to the combination or “roll up” of sub-systems health management tools to create a platform centric system. The document describes the complexity of features that can be considered in the analysis, the different tools and approaches for conducting a CBA and differentiates between military and commercial applications. This document is intended to help those who might not necessarily have a deep technical understanding or familiarity with HM systems but want to either quantify or understand the economic benefits (i.e., the value proposition) that a HM system could provide. Prognostics is a capability within some HM systems that provides an estimation of remaining useful life (RUL) or time to failure and so Prognostic Health Management (PHM) is used where this predictive element exists.
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