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Incorporating Atmospheric Radiation Effects Analysis into the System Design Process

SAE International Journal of Aerospace

Honeywell-Laura Dominik
  • Journal Article
  • 2012-01-2131
Published 2012-10-22 by SAE International in United States
Natural atmospheric radiation effects have been recognized in recent years as key safety and reliability concerns for avionics systems. Atmospheric radiation may cause Single Event Effects (SEE) in electronics. The resulting Single Event Effects can cause various fault conditions, including hazardous misleading information and system effects in avionics equipment. As technology trends continue to achieve higher densities and lower voltages, semiconductor devices are becoming more susceptible to atmospheric radiation effects. To ensure a system meets all its safety and reliability requirements, SEE induced upsets and potential system failures need to be considered.The purpose of this paper is to describe a process to incorporate the SEE analysis into the development like-cycle. Background on the atmospheric radiation phenomenon and the resulting single event effects, including single event upset (SEU) and latch up conditions is provided. The approach to assess radiation effects susceptibility of components and the evaluation of SEE impacts on system functionality is described. The process includes a radiation analysis plan, parts assessment, radiation effects susceptibility evaluation, and a radiation effects report.
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Integrating System and Software Engineering Activities for Integrated Modular Avionics Applications

SAE International Journal of Aerospace

EADS Eurocopter-Frederic Romeas, Olivier TOURILLION
Esterel Technologies-Thierry LeSergent
  • Journal Article
  • 2012-01-2139
Published 2012-10-22 by SAE International in United States
Avionics systems are complex systems that integrate hardware, communication media, have many interactions with other subsystems, within or outside of the aircraft, and for the system discussed in this presentation, integrate software that must be developed according to DO-178B guidelines. System engineering and software engineering are two engineering disciplines that are historically handled by teams with different cultures, and when their engineering processes are supported by tools, use different and incompatible tools. This often leads to a difficult collaboration, with at some point, redundant information and inconsistencies.This presentation introduces a solution, based on the SysML standard for system modeling, and on the SCADE Suite product from Esterel Technologies for the development of DO-178B certified software components. This solution, named SCADE System, allows system and software engineers to work with the right formalism for their respective domains while improving cooperation due to a unified tool framework for System and Software models, the same requirements traceability and documentation generation tools, and a synchronization mechanism for the data that are at the frontier between the two engineering domains.This…
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Fault Detection and Isolation for Electro-Mechanical Actuators Using a Data-Driven Bayesian Classification

SAE International Journal of Aerospace

Moog Inc-Anthony Chirico
Rochester Institute of Technology-Jason R. Kolodziej
  • Journal Article
  • 2012-01-2215
Published 2012-10-22 by SAE International in United States
This research investigates a novel data-driven approach to condition monitoring of Electrical-Mechanical Actuators (EMAs) consisting of feature extraction and fault classification. The approach is designed to accommodate varying loads and speeds since EMAs typically operate under non-steady conditions. Since many common faults in rotating machinery produce unique frequency components, the approach is based on signal analysis in the frequency domain of both inherent EMA signals and accelerometers.The feature extraction process exposes fault frequencies in the signal data that are synchronous with motor position through a series of signal processing techniques consisting of digital re-sampling to the position domain, Power Spectral Density (PSD) computation to the frequency domain, and feature reduction. The reduced dimension feature is then used to determine the condition of the EMA with a trained Bayesian Classifier. Signal data collected from EMAs in known health configurations is used to train the algorithms so that the condition of EMAs with unknown health may be predicted.A passive, linear load test fixture is used to provide a known load (2,400-lbf) on a MOOG industrial MaxForce EMA…
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Health Assessment of Liquid Cooling System in Aircrafts: Data Visualization, Reduction, Clustering, and Classification

SAE International Journal of Aerospace

Hamilton Sundstrand-Rhonda Walthall, Paul DOrlando
University of Connecticut-Shalabh Gupta
  • Journal Article
  • 2012-01-2106
Published 2012-10-22 by SAE International in United States
This paper addresses the issues of data reduction, visualization, clustering and classification for fault diagnosis and prognosis of the Liquid Cooling System (LCS) in an aircraft. LCS is a cooling system that consists of a left and a right loop, where each loop is composed of a variety of components including a heat exchanger, source control units, a compressor, and a pump. The LCS data and the fault correlation analysis used in the paper are provided by Hamilton Sundstrand (HS) - A United Technologies Company (UTC). This data set includes a variety of sensor measurements for system parameters including temperatures and pressures of different components, along with liquid levels and valve positions of the pumps and controllers. A graphical user interface (GUI) is developed in Matlab that facilitates extensive plotting of the parameters versus each other, and/or time to observe the trends in the data. The parameters that reflect interesting information are selected by observing the correlations between different parameters. The data are analyzed using the wavelet transform to highlight the interclass separation and subdue…
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Projecting the Impact of Aircraft Design Decisions on the Performance of a Fuel Cell Power and Energy System in Unmanned Aircraft Systems

SAE International Journal of Aerospace

Protonex Technology Corporation-George Kiwada, Peter Uth
  • Journal Article
  • 2012-01-2178
Published 2012-10-22 by SAE International in United States
Fuel Cells provide an attractive alternative to battery powered Unmanned Aircraft Systems (UAS) as they maintain the simplicity of an all-electric vehicle architecture while taking advantage of highly energy-dense fuels. Unfortunately, the overall energy and power density of the power and energy (P&E) system cannot be determined from the fuel and fuel cell technology without also including the context of the associated aircraft and mission. These outside requirements play a particularly important role in the design of Small UAS (SUAS) P&E systems where the fixed weight of the fuel cell plant may approach or exceed the weight of the fuel utilized. Over the past seven years Protonex has developed fuel cell power systems for a number of different SUAS, creating an empirical database and methodology suitable for future SUAS design efforts.This methodology centers on estimating the weight fractions of the power conversion and energy storage systems in comparison to the overall vehicle weight. The author's previous work focused on presenting this methodology on a macro scale for the initial phases of a conceptual design. As…
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Aircraft Electrical Power Systems and Nonlinear Dynamic Loads

SAE International Journal of Aerospace

Champion Aerospace-John DeWitte Cottingham III
Naval Air Systems Command-Charles Singer, Corinne M. Guernsey, Jason Gousy
  • Journal Article
  • 2012-01-2182
Published 2012-10-22 by SAE International in United States
Aircraft utilize electrical power for many functions ranging from simple devices such as resistive heaters to highly advanced and complex systems responsible for communications, situational awareness, electronic warfare and fly-by-wire flight controls. The operational states of these electronic systems affect safety, mission success and the overall economic expense of operation and maintenance. These electronic systems rely on electrical power within established limits of power quality.In recent years, electrical power quality is becoming excessively degraded due to increased usage of nonlinear and dynamic loads coupled to aircraft power systems that were neither designed nor tested for these loads.Legacy power generation systems were designed for electrical loads with resistive and inductive properties, which previously represented the majority of actual aircraft electrical loads. As more complex and advanced electronic systems were invented, mostly due to developments in semiconductors, the characteristics of electrical load signatures evolved and transitioned from mostly linear to a dominant nonlinear and randomly dynamic composition. This transition to predominantly nonlinear loads is primarily due to the fundamental processing techniques of electrical power from its original…
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Laser/Fiber Optic Based Lighting for Aircrafts

SAE International Journal of Aerospace

RSL Fiber Systems LLC-Giovanni Tomasi
  • Journal Article
  • 2012-01-2145
Published 2012-10-22 by SAE International in United States
Lighting and illumination systems using visible Lasers light sources are being developed under a number of US Navy programs to reduce the ship's costs including acquisition, installation, operation, and maintenance. Recent advances resulting from research initiatives funded thru the Office of Naval Research Mantech program and a Navy SBIR project are making broader applications of this technology feasible, including possible transition into aircrafts for position, landing, anti-collision, cargo loading, wing icing detection, and interior lights. The development of these lasers is being driven by the high definition projection industry, with substantial investments made to bring the technology to broad scale implementation, and with the anticipated increase in product availability and decrease in costs.The laser systems offer significant advantages over fiber optic systems using other light sources including metal halide and LEDs. A laser prototype has provided from a single fiber five times the intensity of an LED from a 37 fibers cable. With a laser system the fiber cable cost is reduced by ~80% and the cable size and weight by ~70%. Lasers are fully…
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Fiber Optic Multi Channel Expanded Beam Connector

SAE International Journal of Aerospace

TE Connectivity, AD&M-Soren Grinderslev
  • Journal Article
  • 2012-01-2108
Published 2012-10-22 by SAE International in United States
To compliment the development of the single channel small form factor size 16 optical Expanded Beam (EB) pin and socket contacts, we have explored the possibility of designing a multi-fiber high density lensed termini (HDLT). This paper describes the design efforts of an insert containing two ferrules accommodating a total of 24 fibers and mountable into a size 8 Quadrax cavity of a 38999 style connector. To take advantage of the expanded beam concept and to keep the design cost effective, the ferrules are molded with a 12 fiber v-groove array positioned behind integral lenses. Originally, the ferrules were designed for the relative benign environment of datacom applications. Therefore, in order to accommodate the broader operational environment of arospace applications which includes mechanical vibration, thermal cycling and high humidity exposure a suitable epoxy had to be identified. Design details, proposed solution, and initial test results are discussed.
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Efficient Certification of Highly Integrated and Complex Aircraft Systems, Such as Integrated Modular Avionics

SAE International Journal of Aerospace

Worldwide Certification Services-Marty Gasiorowski
  • Journal Article
  • 2012-01-2143
Published 2012-10-22 by SAE International in United States
There are several relatively new certification standards related to Integrated Modular Avionics (IMA) certification that have recently been invoked by the certification authorities. These standards include SAE ARP-4754A, Guidelines for Development of Civil Aircraft and Systems, RTCA DO-297, Integrated Modular Avionics (IMA) Development Guidance and Certification Considerations, and RTCA DO-178C, Software Considerations in Airborne Systems and Equipment Certification. RTCA DO-254, Design Assurance Guidance for Airborne Electronic Hardware, and TSO C153, Integrated Modular Avionics Hardware Elements, are also applicable to IMA certification. As many of these standards have only recently been invoked in Advisory Circulars by the Certification Authorities, the industry has little experience in complying with them individually, and even less experience complying with them collectively. With the current trend of increased integration, and the application of IMA architectures to systems that are not avionics, such as electric power, fly-by-wire, and air management, companies that were not previously obligated to consider “avionics” standards will be required to define new processes for their engineering organizations. Further, FAA and EASA have different positions on how these standards…
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An Overview of the EMC Requirements in RTCA/DO-160G

SAE International Journal of Aerospace

Environ Laboratories Llc-Erik Borgstrom
  • Journal Article
  • 2012-01-2147
Published 2012-10-22 by SAE International in United States
RTCA/DO-160G, Environmental Conditions and Test Procedures for Airborne Equipment, prepared by RTCA Special Committee 135, was issued on December 8, 2010, superseding the previous version, DO-160F [1].DO-160G covers standard procedures and environmental test criteria for testing airborne electrical and electronic equipment (avionics). The tests specified in DO-160G are typically performed to meet Federal Aviation Administration (FAA) or other international regulations covering electrical or electronic equipment that is installed on commercial aircraft.The tests and test levels/limits (also referred to as “Equipment Categories”) found in DO-160G are applicable to virtually every type of aircraft in use today, including small general aviation aircraft, business jets, helicopters, regional jets, and “Jumbo Jets” such as the newest airliners from Airbus (the A350XWB) and Boeing (the 747-8).The document includes 26 sections and three appendices, but it is Sections 15 through 23 and also Section 25 that cover Electromagnetic Compatibility (EMC). Examples of other tests covered in DO-160G are: temperature, altitude, vibration, sand/dust, power input, radio frequency susceptibility, lightning, and electrostatic discharge.Creation and revision of DO-160G is coordinated with the European Union…
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