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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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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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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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Powering 270 V DC Equipment from 230 V AC Aircraft Bus

SAE International Journal of Aerospace

Crane Aerospace & Electronics-Kaz Furmanczyk, Mark Stefanich
  • Journal Article
  • 2012-01-2223
Published 2012-10-22 by SAE International in United States
Aircraft electrical power consumption has dramatically increased in recent years. Technological advancements have led to the replacement of traditional hydraulic and pneumatic systems with electrically powered devices. In addition, new functions such as deicing and entertainment systems have been added, which further increases the demand for electrical power. As power needs increase, voltage or current, or both, must be increased. Increased current can be the least desirable result as it leads to larger and heavier wires. To mitigate the issue of wire weight and distribution losses, the latest “More Electric Aircraft” have adopted 230 V ac as the main power bus voltage. However, this presents a problem as a significant amount of existing electrical aircraft equipment (actuators, pumps, etc.) have been designed to use 270 V dc power, which is obtained by a direct rectification of 115 V ac power. Two hundred seventy volts dc cannot be as simply produced from a 230 V ac bus.This paper provides details on new practical ATRU topologies that convert 3-phase 230 V ac into 270 V dc. Designs…
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Parametric Average-Value Converter Modeling for Aerospace Applications

SAE International Journal of Aerospace

Rolls-Royce Corporation-John Timothy Alt
Univ. of Strathclyde-Patrick Norman, Graeme Burt
  • Journal Article
  • 2012-01-2156
Published 2012-10-22 by SAE International in United States
Uncontrolled rectifiers are featured heavily in aircraft electrical power systems performing a number of the power conversion and conditioning functions. Detailed modeling and simulation of these and other converters as part of a wider aircraft power system, whilst accurate, can be very computationally intensive, resulting in impractically slow simulation speed. One potential solution to this issue is the use of average-value converter models, which offer a much lower computational requirement and can utilize larger time steps. Of the average-value diode rectifier modeling methods presented in the research literature the parametric method is particularly well suited to system-level simulation because it can be readily derived to represent all modes of rectifier operation. To date however, published results utilizing this methodology have been limited to simpler power system architectures. In order to assess its applicability for more complex networks, such as those found in modern aircraft systems, more extensive study is required. As such, this paper presents a simulation based evaluation of the flexibility and accuracy of the parametric method for operation in aircraft power systems, considering…
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Development of Lithium-Ion Batteries for Naval Aviation Applications

SAE International Journal of Aerospace

Yardney Technical Products, Inc.-Stuart Santee, Jennifer Currier, Frank Puglia, Joseph Wallace
  • Journal Article
  • 2012-01-2227
Published 2012-10-22 by SAE International in United States
Experimental Lithium-ion (Li-ion) cells were constructed with three different types of Li-ion cathode materials and two different graphitic anodes. The cathode materials were lithium nickel cobalt aluminum oxide, LiNiXCoYAlZO2 (NCA), lithium nickel cobalt manganese oxide, LiNiXCoYMnZO2 (NCM), and lithium iron phosphate, LiFePO4 (FEP). The two graphitic anodes differed only in particle size. The cells were built in lots identified by their cathode and anode materials. The goal was to develop a battery for Naval Aviation applications. Initial testing favored the cells built with an NCM cathode. Further testing was per MIL-PRF-8565/14(AS) with Amendment 1, which resulted in a reduced voltage range during testing favoring the NCA lots. The cells were tested under two different types of cycle life conditions. In both cases, the NCA lots fared best. The NCA lots also had the lowest DC Resistance (DC Res) results (both ≤10 mΩ). One NCA lot experienced no loss in discharge capacity at -20°C after cycling at 70°C, and little loss (-6.5%) after storage at 85°C. That NCA lot was selected for the developmental battery build.
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A Holistic Approach towards Optimizing Energy Storage Response during Network Faulted Conditions within an Aircraft Electrical Power System

SAE International Journal of Aerospace

University of Strathclyde-Puran Rakhra, Patrick Norman, Steven Fletcher, Stuart Galloway, Graeme Burt
  • Journal Article
  • 2012-01-2229
Published 2012-10-22 by SAE International in United States
Within aircraft electrical network designs, energy storage systems (ESS) provide a means of decoupling the electrical-mechanical interactions between the aircraft electrical power system and the aircraft engine, meeting peak load demand and maintaining power quality during network disturbances and variable load conditions. Within the literature to date, control and management strategies of ESSs for such applications has primarily focused on normal network operation with only limited coverage on the behavior of such technologies under abnormal conditions and the subsequent impact on the operation of the wider power system. Through modeling and simulation of a generic aircraft electrical system, this paper will highlight the potential risks of the inherent, sub-optimal operation of certain existing control strategies during fault conditions. It will also discuss the sensitivity of the integrated system response to a number of technological factors including the ESS and wider network converter topologies, protection and control system design, and operational modes. To this end, a holistic approach to optimizing the behavior, control and protection of energy storage during both normal and network faulted conditions is…
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Solid State Power Control as a Network Backbone for Aircraft System Health Management

SAE International Journal of Aerospace

Astronics Corp.-Michael Ballas, Fred Potter
  • Journal Article
  • 2012-01-2233
Published 2012-10-22 by SAE International in United States
Aircraft-level health management requires effective management of data flow. As future aircraft adopt conditioned base maintenance (CBM) and/or integrated vehicle health management (IVHM) protocols, there is need to manage infinitely more data communication on and off the aircraft.This paper explores the idea of employing an Electronic Power Distribution System (EPDS) as a “network backbone” for aircraft-level prognostics. Using EPDS to capture and distribute this data provides a practical solution that minimizes system hardware on future CBM/IVHM enabled aircraft. Employing the Electronic Circuit Breaker (ECB) in a more enhanced sensor state and as a data communication tool, provides tremendous value given its multipurpose capability.A “distributed” electronic power distribution architecture, is comprised of groupings of remotely operated electronic circuit breakers (ECBUs), System Control Interface Units (SCIUs), primary power distribution units (PDU), bus transfer contactors, and so on, all of which will play a future role in aircraft level health management. The ECBUs will be the initial interface for both structural and electrical health sensors. The ECBU will take on an additional data concentrator function, interfacing with a…
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