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Energy Storage: Regenerative Fuel Cell Systems for Space Exploration

Hysytech-Massimiliano Antonini, Manuel Cabrera
Politecnico di Torino-Marco Armandi, Barbara Bonelli, Cristina Zanzottera
Published 2011-10-18 by SAE International in United States
Future exploration missions, including human missions to the Moon and Mars, are expected to have increasingly demanding operational requirements. Generating electrical power, and also maintaining a specific thermal environment, are both critical capabilities for any mission. In the case of exploration, both a wide range of mission types (robotic, human, ISRU etc.) and a variety of environments exist: from interplanetary space, to the shadow of a lunar crater, to the attenuated and red-shifted lighting on the Martian surface, power requirements must be met. This objective could be met with different technologies. The choice is dictated by the operating conditions and the different types of mission. TAS-I is historically mainly involved in missions related to the space exploration with the presence of astronauts. A typical example is the exploration of the Moon with the installation on the Moon surface of a base inclusive of pressurized habitats and rovers. For this kind of application it has been identified as potential candidate the utilization of Regenerative Fuel Cell (RFC) System. The RFC is an electrochemical system that collects…
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Incorporation of Atmospheric Neutron Single Event Effects Analysis into a System Safety Assessment

SAE International Journal of Aerospace

Honeywell-Laura Dominik
Rockwell Collins, Inc.-Mike Dion
  • Journal Article
  • 2011-01-2497
Published 2011-10-18 by SAE International in United States
Atmospheric Neutron Single Event Effects (SEE) are widely known to cause failures in all electronic hardware, and cause proportionately more failures in avionics equipment due to the use altitude. In digital systems it is easy to show how SEE can contribute several orders of magnitude more faults than random (hard) failures. Unfortunately, current avionics Safety assessment methods do not require consideration of faults from SEE. AVSI SEE Task Group (Aerospace Vehicle Systems Institute Committee #72, on Mitigating Radiation Effects in Avionics) is currently coordinating development of an atmospheric Neutron Single Event Effects (SEE) Analysis method. This analysis method is a work in progress, in close collaboration with SAE S-18 and WG-63 Committees (Airplane Safety Assessment Committee). The intent is to include this method as part of current revisions to ARP4761 (Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment).
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A Model-based Solution to Robust and Early Detection of Control Surface Runaways

SAE International Journal of Aerospace

Airbus-Philippe Goupil, Rémy Dayre, Hervé Le Berre
IMS-Ali Zolghadri, Anca Gheorghe, Jérôme Cieslak, David Henry
  • Journal Article
  • 2011-01-2803
Published 2011-10-18 by SAE International in United States
This paper discusses the design of a model-based fault detection scheme for robust and early detection of runaways in aircraft control surfaces servo-loop. The proposed scheme can be embedded within the structure of in-service monitoring systems as a part of the Flight Control Computer (FCC) software. The final goal is to contribute to improve the performance detection of unanticipated runaway faulty profiles having very different dynamic behaviors, while retaining a perfect robustness. The paper discusses also the tradeoffs between adequacy of the technique and its implementation level, industrial validation process with Engineering support tools, as well as the tuning aspects. The proposed methodology is based on a combined data-driven and system-based approach using a dedicated Kalman filtering. The technique provides an effective method ensuring robustness and good performance (well-defined real-time characteristics and well-defined error rates). Simulation results, using In-flight recorded data sets provided by Airbus, are presented to demonstrate the potential of the developed technique.
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Cooperative Robots for Full Automation

Alema Automation-Philippe Prat, Etienne Gueydon
Published 2011-10-18 by SAE International in United States
Alema Automation is a company which has a long experience with single robots solutions working in cooperation with an operator for drilling and filling fasteners in aerospace.Based on that experience, we have developed full automation solutions involving 2 robots working in cooperation. These robots are able to manage clamping force on flexible assemblies to avoid burrs, delamination and, in addition, to install 2 sides fasteners.So far industrial robot controllers for cooperating robots have been based on 2 separate controllers requiring specific software from the robotic integrator in order to control the cooperation between robots.Today a key cooperative feature is included in the package delivered by the robot supplier. Thus, it avoids complex programming from the integrator and specific development for cooperation to get more efficient application and also improvement on cycle time.Alema Automation development has been made on both off line programming as well on calibration to provide cooperative robotic cells which perform installation of solid rivets.Master robots are up to drill, insert and hammer solid rivets.Slave robots are up to manage the bucking bar.…
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Mathematical Model of Water Contamination in Aircraft Fuel Tanks

Airbus-Joseph Kah-Wah Lam
Stirling Dynamics Limited-Stephen Tomlinson, Matt Barker, Darran Venn, Luke Hickson
Published 2011-10-18 by SAE International in United States
Water is a contaminant that can lead to fuel system icing, microbial contamination, corrosion and fuel quantity gauging problems and therefore an efficient water management system is required in order to maximise the performance of an aircraft's fuel system. This paper describes a time-transient aircraft fuel tank model with water contamination, due to the principal mechanisms of dissolution, suspension, condensation and transportation. The tank model presented is a component of the NEPTUNE fuel system model which was developed for Airbus using the A380 as an example aircraft. A description of the physics of water contaminated fuel is given and of how this has been incorporated into a mathematical model of an aircraft fuel tank. A modular approach is demonstrated which enables interconnecting fuel tanks to be configured in larger systems in a flexible and easily understood manner.
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Audio/Video and Hard Real-Time Capability for Advanced IMA Architectures

SAE International Journal of Aerospace

TTTech. Computertechnik AG-Mirko Jakovljevic
  • Journal Article
  • 2011-01-2699
Published 2011-10-18 by SAE International in United States
The design of complex integrated systems and avionics architectures relies on the system architect's capability to manage key system interfaces, and share computing and networking resources. The capability of Ethernet-based ARINC 664 avionics networks to handle critical traffic with μs-jitter and fixed latency can be expanded using the Layer 2 Quality Of Service (QoS) protocol enhancements described in SAE AS6802. All existing critical distributed functions using ARINC 664 Virtual Links (VLs) can operate without congestion and with prescribed maximum latencies.This paper discusses basic considerations for how time-triggered services based on AS6802 standard could enable integration of hard real-time and audio/video capabilities in advanced ARINC 664-based IMA architectures. In order to adapt those capabilities to existing design processes for ARINC 664 networks, time-triggered services described in SAE AS6802 can be modeled as periodic ARINC664 traffic with μs-jitter and fixed latency.Both standards integrated on one switch establish Ethernet as the deterministic unified Ethernet technology for time-, safety-, and mission-critical applications, capable of handling any low-jitter, low-latency and lossless applications. Finally, an overview is provided which shows how…
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Transient Thermohydraulic Modeling of Capillary Pumped Loop

Hispano Suiza-Nicolas Delalandre, Jacques Salat
P' institute-Vincent Ayel
Published 2011-10-18 by SAE International in United States
“More electric” aircraft requires more power electronics integration. Traditional cooling systems reach their maximal performances because of too high thermal dissipation of these components. Thanks to their heat transport capacity and their passive pumping, two-phase fluid capillary pumped loops appear among identified alternative solutions. Before being used in aircrafts, some investigations are needed to estimate the ability of these systems to ensure thermal transfer under harsh environment: vibrations, accelerations, cooling temperature range … If lots of steady state modeling are available in the literature, few transient models exist. However, transient phases set the main problem for two-phase fluid capillary pumped loops in airplane environment. This paper proposes a transient thermohydraulic modeling approach of a capillary pumped loop developed for gravitational applications: the Capillary Pumped Loop for Integrated Power (CPLIP).As hydraulic transfers are the driving phenomena during transient states, the present model transcribes accurately the fluid mechanical aspects. It relies on mass, momentum and energy conservation equations, using finite volumes method. Mass enthalpy, pressure and mass flow rate are considered as variables. Temperature is calculated thanks…
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Multidisciplinary Optimization under Uncertainty for Preliminary Aircraft Sizing

Universite Paul Sabatier-Laure Jaeger, Christian Gogu, Stéphane Segonds, Christian Bes
Published 2011-10-18 by SAE International in United States
The robust optimization allows designing an optimal system whose performances are insensitive to uncertainties. On the other hand reliability based optimization determines a minimum level of reliability but makes no guarantee regarding the performance sensitivity to uncertainties. In this paper a method combining both approaches is developed and is illustrated by an application to preliminary aircraft design. Uncertainties are taken into account through a probabilistic approach stemming from the use of historical data of aircraft (features, performances, etc.). Firstly, one shows that taking into account uncertainties with a constant standard deviation from the residual errors of the database, generates non-physical results because it leads to too large uncertainties in some regions. To overcome this problem one then develops an uncertainty model with a variable standard deviation which can take into account two factors: on one hand, the number of historical data in a given region varies; on the another hand some areas are less well predicted by the analytical model functions. The developed uncertainty modeling is applied to preliminary aircraft design optimization under both reliability…
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An Overview of Scientific and Technical Literature on Coanda Effect Applied to Nozzles

Universita' di Modena e Reggio Emilia-Michele Trancossi
Published 2011-10-18 by SAE International in United States
In 1911 the first fundamental patent of Henry Coanda has been submitted. And 2011 is the centenary of this event for aeronautic history. This paper presents a general review of applied research about Coanda effect nozzles, starting from earlier Coanda works to today's applications. Coanda effect based nozzles are considered, looking at the nozzles which can produce an effective angular deflection of a jet and in particular of a synthetic jet produced by two or more jets.
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An LPV Approach H / H Robust FDD for Aircraft Actuator Systems

University of Hull-Lejun Chen PhD, Ronald Patton
Published 2011-10-18 by SAE International in United States
This work is motivated through a research study ADDSAFE funded by the European Commission, following an interest in implementing mixed linear parameter varying (LPV) H_/H✓ model-based fault detection and diagnosis (FDD) methodology for detecting nonlinear actuator faults for flight control system. The main design goal is to maximize the robustness of the residual signal to uncertainty and disturbances whilst also achieving the specific minimum sensitivity of the residual signal to faults. The specific minimum sensitivity index used is based on the H_ index concept and is extended to the LPV FDD system problem. This allows the fault signature for multiple sensor and actuator faults to be reconstructed simultaneously, facilitating the robust isolation of faults rather than just their detection. Instead of using constant gains, parameter-varying gains are used in the LPV observer and the free design parameters generated, through using the generalized inverse, can be parameterized to improve the conservatism of finding the robust solution. This approach is combined within the standard quadratic LPV framework. The FDD approach developed is then applied in non-linear simulation…
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