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Technical Paper
2014-09-16
Richard Mourn
Abstract The paper provides an introduction into IEEE-1394, AS5643 and related documents. It then explores the I/O Technology Suitability Study criteria used to originally select IEEE-1394b (Beta) as the Vehicle System Data Bus for the F-35 Joint Strike Fighter and update each criterion with new information based on more than a decade of experience and use in not only the F-35 but several other programs. Based on the suitability study criteria, the reader gains insight into how and why programs like the F-35, which implements dozens of AS5643/IEEE-1394 devices per plane, utilize AS5643/IEEE-1394 for its 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 remote nodes. 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.
Technical Paper
2014-09-16
Yamina Boughari, Ruxandra Botez, Georges Ghazi, Florian Theel
Abstract The main goal of this flight control system is to achieve good performance with acceptable flying quality within the specified flight envelope while ensuring robustness for model variations, such as mass variation due to fuel burn. The Cessna Citation X aircraft linear model is presented for different flight conditions to cover the aircraft's flight envelope, on which a robust controller is designed using the H-infinity method optimized by two heuristic algorithms. The optimal controller was used to achieve satisfactory dynamic characteristics for the longitudinal and lateral stability control augmentation systems with respect to this aircraft's flying quality requirements. The weighting functions of the H-infinity method were optimised by using both genetic and differential evolution algorithms. The evolutionary algorithms gave very good results. This is the first time these algorithms have been used in this form to optimize H-infinity controllers on a business aircraft, respecting both flying quality requirements and robustness criteria as objective functions and avoiding the use of other computationally complicated algorithms.
Technical Paper
2014-09-16
Mario Luca Fravolini, Matthew Rhudy, Srikanth Gururajan, Silvia Cascianelli, Marcello Napolitano
Abstract 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-static tube could induce an incorrect feedback control action, potentially leading to the loss of control of the UAV. 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-static tube sensor. The first approach is based on an Extended Kalman Filter (EKF) and the second approach is based on Least Squares (LS) modeling. The EKF technique utilizes nonlinear kinematic relations between GPS, Inertial Measurement Unit and Air Data System signals and has the advantage of independence from knowledge of the aircraft model. The LS method is based on explicit knowledge of the aircraft model and has the advantage of on-line computation of the airspeed estimate, with minimal computational effort.
Technical Paper
2014-09-16
Srikanth Gururajan, Mario Luca Fravolini, Matthew Rhudy, Antonio Moschitta, Marcello Napolitano
Abstract 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, a failure on one sensor could 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. Analytical redundancy is provided through a least squares modeling based approach and an extended Kalman filter approach to handle the Sensor Failure Accommodation (SFA) task.
Technical Paper
2014-09-16
Jay Wilhelm, Joseph Close, Wade Huebsch
A Hybrid Projectile (HP) is a ballistically launched round that transforms into an Unmanned Aerial Vehicle (UAV) at a designated point during flight. Aerodynamic control surfaces and associated control laws were sought that would extend the projectile's range using body lift and include guidance for a selected point of impact. Several challenges were encountered during the modification of an existing projectile, in this case a 40mm round, to achieve range extension and controllability. The control surfaces must be designed to allow for de-spin, controllability, and natural static stability. Also, a control system with laws and guidance relationships between heading, pitch or glide rate, and the associated aerodynamic surface movements needed to be developed. The designed aerodynamic surfaces, external ballistics, and control methods developed were modeled in a projectile flight simulator built in MATLAB. The base model was an M781 practice round and the aerodynamic coefficients and mass data were found in literature.
Technical Paper
2014-09-16
Nicholas Ernest, Kelly Cohen, Corey Schumacher, David Casbeer
Abstract Looking forward to an autonomous Unmanned Combat Aerial Vehicle (UCAV) for future applications, it becomes apparent that on-board intelligent controllers will be necessary for these advanced systems. LETHA (Learning Enhanced Tactical Handling Algorithm) was created to develop intelligent managers for these advanced unmanned craft through the novel means of a genetic cascading fuzzy system. In this approach, a genetic algorithm creates rule bases and optimizes membership functions for multiple fuzzy logic systems, whose inputs and outputs feed into one another alongside crisp data. A simulation space referred to as HADES (Hoplological Autonomous Defend and Engage Simulation) was created in which LETHA can train the UCAVs intelligent controllers. Equipped with advanced sensors, a limited supply of Self-Defense Missiles (SDM), and a recharging Laser Weapon System (LWS), these UCAVs can navigate a pre-defined route through the mission space, counter enemy threats, and destroy mission-critical targets.
Technical Paper
2014-09-16
Aurelie Beaugency, Marc Gatti, Didier Regis
Abstract 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. 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 complexity of avionics systems, which integrate more and more functions, have encouraged new players to enter the market. The aim of this article is to analyze how technological changes can affect the competitiveness of avionics firms. We refer to criticality levels as a determinant of the market competitiveness. Certification processes and costs could stop new comers to bring innovations from the consumer electronics industry and protects traditional players. The study will compare three avionics systems regarding their patent dynamics since 1980: flight controls, Integrated Modular avionics and Head-Up Displays.
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
Martin Bradish, Obed Sands, Ted Wright, Casey Bakula, Daniel Oldham, William Ivancic, Michael Lewis, Joseph Klebau, Nicholas Tollis, Andrew Jalics
Abstract This paper summarizes the Power, Avionics and Software (PAS) 1.0 subsystem integration testing and test results that occurred in August and September of 2013. This paper covers the capabilities of each PAS assembly to meet integration test objectives for non-safety critical, non-flight, non-human-rated hardware and software development. This test report is the outcome of the first integration of the PAS subsystem and is meant to provide data for subsequent designs, development and testing of the future PAS subsystems. The two main objectives were to assess the ability of the PAS assemblies' to exchange messages and to perform audio tests of both inbound and outbound channels. This paper describes each test performed, defines the test, the data, and provides conclusions and recommendations.
Technical Paper
2014-09-16
Prashant Vadgaonkar
Abstract Today's digital avionics systems leverage the use of the Embedded COTS (Commercial Off The Shelf) hardware to fit the need of small form factor, low power, reduced time to market and reduced development time with efficient use of DO-254 for compliance of product. COTS modules are entering in digital avionics systems such as COM (Computer On Module)/SOM (System On Module)/SIP (System In Package) with huge advancement in semiconductor and packaging industry. In today's scenario COTS are very useful for DAL (Development Assurance Level) C and below as the efforts on compliance for DAL A and B are huge. This paper proposes to use these for DAL A and B as well, where one can get enormous benefit on efforts of compliance and time to market. This paper makes an attempt to explain the current scenario of the Embedded COTS usage in Avionics Systems. This paper also brings the study of the selection process of Embedded COTS along with the important selection parameters, constraints, challenges and guidelines.
Technical Paper
2014-09-16
Gene Tu, Wei Shih, Walter Yuen
Abstract To meet pulse power mode component cooling application needs, we developed, fabricated and tested a concept to use energy storage material and phase change material to enhance the heat dissipation of a conventional heat sink. Test results demonstrated the ESM/PCM heat sink has unique thermal performance. Under the same working condition, the peak temperature of ESM/PCM heat sink is 1.5°C lower than of a conventional heat sink. An optimized design can lead to a significant weight reduction for the heat sink in applications with high peak load and low duty power cycle power.
Technical Paper
2014-09-16
Gregory J. Moore, Frank Puglia, Lawrence Myron, Stephen Lasher, Bob Doane, Joe Gnanaraj, Seth Cohen, Arthur Dobley, Ryan Lawrence, Rong Yan
Abstract For 70 years Yardney has been a leader in specialty battery and energy systems for military, space, avionics, weapon systems and undersea vehicles. In addition to battery systems, Yardney also delivers hybrid systems for ground, space, undersea and avionic applications. The beauty of hybrid systems, combining energy sources such as batteries, capacitors, fuel cells and solar, is that they can be used to optimize energy and power density, and with proper design, the systems can also lead to longevity of components and an overall cost savings. For ground applications, utilization of hybrid systems can assist in conservation of fuel by making vehicle applications more efficient. For space applications, satisfying pulses can be improved by a capacitor and battery hybrid energy storage system. To optimize aircraft performance and decrease operating costs, avionics are beginning to move towards more electric aircrafts (MEA). This embraces the concept of utilizing electrical power for driving aircraft subsystems currently powered by mechanical means.
Technical Paper
2014-09-16
Evan Racine, Zachary Lammers, Street Barnett, John Murphy, Quinn Leland
Abstract The purpose of this study is to set up a laboratory test apparatus to analyze aircraft flight control EMAS' electrical and thermal energy flow under transient and dynamic flight profiles. A hydraulic load frame was used to exert load to the EMA. The actuator was placed within an environmental chamber which simulates ambient temperature as function of altitude. The simulated movement or stroke was carried out by the EMA. The under test EMA's dynamic load, stroke, and ambient temperature were synchronized through a real time Labview DAQ system. Motor drive voltage, current, regenerative current, and motor drive and motor winding temperature were recorded for energy analysis. The EMA under test was subjected to both transient and holding load laid out in a test matrix. It was found that the transient missions of EMAS presented the most electric demand on the aircraft electric power supply system while holding presented the most severe thermal stress on the EMAS, where the EMAS operated at 0% efficiency and all the electric power converted to heat.
Technical Paper
2014-09-16
Riko Bornholdt, Frank Thielecke
Abstract Due to a shift of the major aviation concerns to focus on enhancements of the successful programs instead of pushing their successors, the need for new methodologies for aircraft system architecture design emerges. Challenging the existing requirements and reconsidering the functions and their allocation could help to dissolve the system specific development paradigm and lead to beneficial architecture concepts. To help understand the mechanisms and boundary conditions of developing fault-tolerant systems, the first part of the paper gives an overview of the successive process of architecture design. The significant architectural design decisions and the concurrent safety assessment process are discussed. One crucial step in the design space exploration of future aircraft system architectures is the allocation of the consumers to the available power sources. Within the paper a methodology for the optimization of the power allocation for flight control systems is proposed. With this methodology the evaluation of a large amount of architecture permutations on the basis of a preliminary system safety assessment regarding multiple top failure events is possible in a short time period.
Technical Paper
2014-09-16
Andrew Slippey, Michael Ellis, Bruce Conway, Hyo Chang Yun
Abstract Carbon fiber reinforced polymer (CFRP) composite material is an attractive structural material in applications where mass is critical. The carbon fiber matrix provides strength comparable to steel with only 25% of the density. The CFRP sheet can often also be made thinner than metal with similar mechanical properties, further increasing the mass savings. However, thermal challenges have arisen with the increased use of composites. In the area of electronics enclosures, traditional metal structures conduct and spread heat over large surfaces, but composites act as insulation. Heat generated by components causes internal temperatures to rise and has detrimental impact on the performance and reliability of the electronics. A method is proposed and tested that utilizes constant conductance heat pipes (CCHPs) that penetrate through the CFRP walls. The CCHPs are capable of transporting significant heat energy through a limited cross-section with a minimal temperature penalty. CCHPs are passive, two-phase, thermal transport devices which have extremely high effective thermal conductivities on the order of thousands of W/m-K.
Technical Paper
2014-09-16
Michael Ellis, William Anderson, Jared Montgomery
Under a program funded by the Air Force Research Laboratory (AFRL), Advanced Cooling Technologies, Inc. (ACT) has developed a series of passive thermal management techniques for cooling avionics. Many avionics packages are often exposed to environment temperatures much higher than the maximum allowable temperatures of the electronics. This condition prevents the rejection of waste heat generated by these electronics to the surrounding environment and results in significant ambient heat gain. As a result, heat must be transported to a remote sink. However, sink selection aboard modern aircraft is limited at best. Often, the only viable sink is aircraft fuel and, depending on mission profile, the fuel temperature can become too high to effectively cool avionics. As a result, the electronic components must operate at higher than intended temperatures during portions of the mission profile, which reduces component lifetime and significantly increases the probability of failure. To address this issue, ACT developed two passive thermal management approaches for avionics packages: heat pipe assemblies to reduce the internal temperature gradient and a Loop Heat Pipe (LHP) to transport thermal energy to alternative sinks.
Technical Paper
2014-09-16
Massimo Conte, Michele Trancossi
Abstract This paper introduces a new equipment, which allows autonomous landing and docking of a VTOL aircraft and any mobile system. It has been studied and developed inside the MAAT (Multibody Advanced Airship for Transport) EU FP7 project to control autonomous docking of manned cruiser and feeder airships in movement. After a detailed analysis it has been verified that It could be considered a technological spin off the MAAT project. It defines a new instrumental system for governing relative positioning between a movable target and VTOL air vehicles, such as helicopters, airships and multi-copters. This solution is expected to become a short time to market equipment for helicopters (both manned and unmanned) ensuring autonomous landing ability even in case of low visibility. Infrared emitters allow controlling both position and yaws angle. It is in advanced testing phase after a preliminary successful testing using a quadcopter. Tests has produced autonomous landing on a small platform mounted on an unmanned vehicle.
Technical Paper
2014-09-16
Prashant Vadgaonkar, Ullas Janardhan, Adishesha Sivaramasastry
Abstract 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 today's scenario, sensors are hardwired. The number of sensors is growing due to automation which increases the accuracy of intended Aircraft functions. Sensors are distributed all over the Aircraft and they are connected through wired network for signal processing and communication. LRUs (Line Replaceable Unit) which are integrating various sensors also use a wired approach for communication. The use of a wired network approach poses challenges in terms of cable routing, stray capacitances, noise, mechanical structure and added weight to the structure. The weight of cables contributes significantly to the overall weight of the aircraft. As the weight of Aircraft increases, the required fuel quantity also increases. The Key driver for Airline operational cost is fuel. Fuel quantity is a direct function of weight.
Book
2014-09-03
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
2014-07-31
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.
Standard
2014-07-01
This SAE Aerospace Recommended Practice (ARP) is an application guide for fixed and variable displacement hydraulic motors. It provides details of the characteristics of fixed and variable displacement hydraulic motors, architectures, circuit designs, controls, and typical applications. The applications include airborne and defense vehicles with emphasis on high performance applications.
WIP Standard
2014-07-01
This document contains three annexes to the SAE AS5506 Standard - the SAE Architecture Analysis and Description Language. The first annex, Annex A Graphical AADL Notation, defines a set of graphical symbols for the graphical AADL notation. These graphical symbols can be used to express relationships between components, features, and connections in an AADL model. Graphical AADL diagrams are legal in accordance with the AADL core standard if the AADL model being presented graphically is legal and if the correct graphical symbols are used. For example, a graphical editor is not permitted to create a connection whose source and destination are not connected. Graphical presentations of AADL models are permitted to show subsets of legal AADL models. For example, property values may be entered through a property sheet or dialog box. The figures in this annex present different views of an AADL model. These views are not prescriptive, but intended to illustrate possible views and layouts. The second annex, Annex C AADL Meta Model and Interchange Formats, defines the AADL meta model and XML-based interchange formats for AADL models.
WIP Standard
2014-06-24
This document discusses, in broad general terms, typical present instrumentation practice for post-overhaul gas turbine engine testing. Production engine testing and engine development work are outside the scope of this document as they will typically use many more channels of instrumentation, and in most cases will have requirements for measurements that are never made in post-overhaul testing, such as fan airflow measurements, or strain measurements on compressor blades. The specifications for each parameter to be measured, in terms of measurement range and measurement accuracy, are established by the engine manufacturers. Each test cell instrument system should meet or exceed those requirements. Furthermore, each instrument system should be recalibrated regularly, to ensure that it is still performing correctly.
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