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2015-09-29
Technical Paper
2015-01-2846
Chunshan Li, Guoying Chen, Changfu Zong, Wenchao Liu
This paper presents a fault-tolerant control (FTC) algorithm for four-wheel independently driven and steered (4WID/4WIS) electric vehicles. The Unscented Kalman Filter (UKF) algorithm is utilized in the fault detection and diagnosis (FDD) module so as to estimate the in-wheel motor parameters, which could diagnose parameters variations caused by in-wheel motor fault. A sliding mode controller (SMC) is able to compute the generalized forces/moments to follow the desired vehicle motion. By considering the tire adhesive limits, a reconfigurable control allocator optimally distributes the generalized forces/moment among healthy actuators so as to minimize the tire workloads once the actuator fault is detected. An actuator controller calculates the driving torques of the in-wheel motors and steering angles of the wheels in order to finally achieve the distributed tire forces. If one or more in-wheel motors lose efficacy, the FDD module diagnoses the actuator failures first.
2015-09-29
Technical Paper
2015-01-2879
Evandro Silva
In recent years the commercial vehicle industry, specifically the heavy duty truck product line, has seen a rapid increase in the replacement of pure mechanical systems by electronic controlled systems. Engine, transmission, brakes, lighting, clusters, etc. are all monitored and/or controlled electronically. The adoption of electronic systems created a substantial change in the complexity of our products. Currently Diagnostic Trouble Codes (DTC) displayed on instrument clusters, in the majority of the cases, are no longer generated by a single sensor/component failure, instead these DTCs are triggered by a system monitor flag, result of a below average performance or a failure of an entire system. This new level of complexity makes it very difficult for the current diagnostic methods and tools, to identify what is causing the equipment to operate below ideal conditions.
2015-09-29
Technical Paper
2015-01-2728
Paul C. Cain
OEM benefit: Vehicle manufacturers desire continuous feedback in monitoring key safety sub-assemblies. In this application, engineers are calculating the remaining brake pad life by monitoring the current thickness of the brake pad friction material. This information is used in scheduling preventative maintenance activities and avoiding safety incidents. Unplanned machine down time and field repair costs in earthmoving equipment is cost prohibitive. This technology allows OEM's to have high confidence, continuous feedback on this critical vehicle safety feature avoiding expensive, unplanned repairs and improving field "up time" performance. Application challenge: Developing a reliable linear position sensor that is suitable for continuous monitoring of brake pad material thickness in a high pressure, high temperature, high vibration and contaminated environments typical of large construction (earthmoving) vehicles.
2015-09-22
Book
Ian K. Jennions, Samir Khan, Paul Phillips, Chris Hockley
Today, we are all strongly dependent on the correct functioning of technical systems. They fail, and we become vulnerable. Disruptions due to degradation or anomalous behavior can negatively impact safety, operations, and brand name, reducing the profitability of all elements of the value chain. This can be tolerated if the link between cause and effect is understood and remedied. Anomalous behavior, which indicates systems or subsystems not acting in accordance with design intent, is a much more serious problem. It includes unwanted system responses and faults whose root cause can’t be properly diagnosed, leading to costly, and sometimes unnecessary, component replacements. The title No Fault Found: The Search for the Root Cause was developed to propose solutions to this technical and business challenge, which has become less and less acceptable to the commercial aviation industry globally.
2015-09-15
Technical Paper
2015-01-2473
Alessandro Ceruti, Alfredo Liverani, Piergiovanni Marzocca
Traditional User/Maintenance Manuals provide useful information when dealing with simple machines. However, when dealing with complex systems of systems and highly miniaturized technologies, like UAVs, or with machines with millions of parts, a commercial aircraft is a case in point, new technologies taking advantage of Augmented Reality can rapidly and effectively support the maintenance operations. This paper presents a User/Maintenance Manual based on Augmented Reality to help the operator in the detection of parts and in the sequence to be followed to assemble/disassemble systems and subsystems. The proposed system includes a handheld device and/or an head mounted display or special goggles, to be used by on-site operators, with software management providing data fusion and overlaying traditional 2D user/maintenance manual information with an augmented reality software and appropriate interface.
2015-09-15
Technical Paper
2015-01-2589
Julien Feau, Philippe Chantal, Jayant Sen Gupta
Modern aircrafts, such as A380 or A350 for Airbus, are very well connected to ground stations through wireless communications. For maintenance and operations purpose, the aircraft is programmed to send regularly information such as flight reports based on the BITE messages (Built-In Test Equipments) or standard reports based on the value of physical parameters. Moreover, Airbus is capable of sending requests (called uplinks) to the aircraft to retrieve the value of different parameters in almost real-time. This ability, associated with adequate process, improves significantly the reaction time of the diagnostic and prognostic solutions that Airbus can provide to its customers. Traditionally Health Monitoring is considered useful when the Potential to Functional failure (P-F) interval is greater than one flight cycle.
2015-09-15
Technical Paper
2015-01-2440
Robert Moehle, Jason Clauss
From the dawn of commercial air travel until 2001, labor costs loomed as the greatest expense in commercial aviation. Though fuel costs have since taken the top spot, labor costs remain a pressing area of concern in the airline industry. Airlines have long sought to reduce the burden of labor to improve the businesses’ bottom line. One of their most frequent appeals has been to allow a single flight crew member to operate the aircraft. Safety concerns represent the dominant barrier to single-pilot Part 121 operations. The FAA and Congress consistently demonstrate a bias toward conservatism in their regulation of airlines and commercial aircraft. Under-educated on the true failure rates, bureaucrats and the general public fall prey to isolated news stories about pilots becoming ill or falling asleep in the flight deck. Yet, in an alarming spate of recent airline accidents, the presence of multiple crewmembers did nothing to prevent, and actually may have contributed to, the crash.
2015-09-15
Technical Paper
2015-01-2582
Andre Silva, Nayeff Najjar, Shalabh Gupta, Paul D'Orlando, Rhonda Walthall
The main function of the Environmental Control System (ECS) is to deliver thermal control and cabin pressurization of the air for the comfort and safety of crew members and the passengers on-board. The Heat Exchanger of the ECS is the critical component that ensures healthy system operation and maintains this key function. The heat exchanger mainly exhibits the failure known as fouling, which is the accumulation of clogging due to contamination. For safe and efficient operation of the ECS under the complex environments of aerospace systems, it is necessary to develop the capability to diagnose degradation of system components in the early phase of fault evolution. Periodic maintenance of these components without knowledge of their remaining useful life estimates causes significant financial expenses for the airliners and unnecessary interruption of aircraft operation.
2015-09-15
Technical Paper
2015-01-2397
Angelo C. Conner, Luis Rabelo
In planning, simulation models create microcosms, small universes that operate based on assumed principles. And while this can be powerful, the information it can provide is limited by the assumptions made and the designed operation of the model. When performing schedule planning and analysis, modelers are often provided with timelines representing project tasks, their relationships, and estimates related to durations, resource requirements, etc. These timelines can be created with programs such as Microsoft Excel or Microsoft Project. There are several important attributes these timelines have; they represent a nominal flow (meaning they do not represent stochastic processes), and they are not necessarily governed by dates or subjected to a calendar. Attributes such as these become important in project planning since timelines often serve as the basis for creating schedules.
2015-09-15
Technical Paper
2015-01-2585
Tuur Benoit, Yves Lemmens, Wim Desmet PhD
Modern aircraft have many sensors onboard that are used for both control of the aircraft and monitoring the aircraft’s condition. For health monitoring applications, nowadays, an assessment is performed in order to detect the criticality of the loads on the aircraft’s structure using look-up charts or neural network algorithms based on external parameters such as vertical and lateral acceleration, aircraft mass, roll, pitch, and yaw rate (Wilson, 2013). However, since the conditions of the real event in general will differ from the simulations used to create the look-up charts or neural networks, these black-box approaches are limited in their capability of classifying events. This paper proposes a solution for utilizing multi-body models in nonlinear state observers, to directly estimate the loads acting on the aircraft structure from measurement data of sensors that are commonly available on modern aircraft, such as accelerometers on the wing, rate gyros and strain gages.
2015-09-15
Technical Paper
2015-01-2593
Jonathan L. Geisheimer, Michael Wabs, Carlos Carvalho
Time Domain Reflectometery (TDR) has been used for many years to find cable breaks and measure fluid levels in industrial processes. The technology uses picosecond level pulses and the associated reflection off of the fluid level surface in a time of flight measurement to determine fluid height. However, TDR signals have additional information that can be processed and exploited for IVHM applications. For example, when water collects in the fuel tank, TDR is capable of identifying and measuring the amount of water. This can allow for water sumps to be drained on condition instead of on a schedule. In addition, electromagnetic properties of the fluid can be determined, such as the dielectric constant and conductivity, which can be used to identify mis-fueling situations, contaminants in the fluid, and potentially other properties of fluid health.
2015-09-15
Technical Paper
2015-01-2401
Michael Schmidt, Philipp Nguyen, Mirko Hornung
The projected uptick in world passenger traffic challenges the involved stakeholder to optimise the current aviation system and to find new solutions being able to cope with this trend, since especially large hub airports are congested and operate at their capacity limit. Delays due to late arrival of aircraft or unreliable and inefficient ground operation processes would disrupt the airport operations tremendously. Various concepts improving the current turnaround processes have been presented thus far, whereby radical aircraft design changes have little chances for realization. Based on a clustering of aircraft interfaces, such as doors and services panels, for state-of-the-art passenger aircraft, concepts targeting to reduce the required resources and time are presented. By maintaining the established overall aircraft configuration, the concepts promote higher probability to become commercially available for aircraft manufactures and operators.
2015-09-15
Technical Paper
2015-01-2584
Andrew Dickerson, Ravi Rajamani, Mike Boost, John Jackson
Based on a advanced modeling approach, we are developing a system for estimating the remaining useful life (RUL) for Li-Ion batteries for aerospace applications. We begin with a set of functional requirements that are further translated to detailed system and maintenance specifications. We will show how this RUL calculator will be translated to actual algorithms and operating procedures inside a battery’s management unit. Test data will be used to validate the robustness and goodness in the predictions. We will also share plans for the future along with implications for certification of the system. This is important because batteries are governed by FAA regulations and are dispatch critical for certain applications.
2015-09-15
Technical Paper
2015-01-2592
Joao Pedro Malere, Wlamir Olivares Loesch Vianna
This paper presents a method to determine the root cause of an aircraft component failure by means of the aircraft fault messages history. The k-Nearest Neighbors (k-NN) and the Tree-Augmented naive Bayes (TAN) methods were used in order to classify the failure causes as a function of the fault messages (predictors). The contribution of this work is to show how well the fault messages of aircraft systems can classify specific components failure modes. The training set contained the messages history from a fleet and the root causes of a butterfly valve reported by the maintenance stations. A cross-validation was performed in order to check the loss function value and to compare both methods performance. It is possible to see that the use of just fault messages for the valve failure classification provides results that close to 2/3 and could be used for faster troubleshooting procedures.
2015-09-15
Technical Paper
2015-01-2590
Yufei Lin, Zakwan Skaf, Ian Jennions
In the past few decades aircraft systems have become increasingly more complex, and require continuous monitoring and real-time assessment during operation. Under these conditions, it is obvious that the next generation of airplanes will undergo substantial changes and will make significant technical progress to improve operational safety and efficiency. This vision is entirely consistent with the adoption of Integrated Vehicle Health Management (IVHM) technology which uses merging of interdisciplinary trends to carry out safe and effective vehicle operation. Hitherto, IVHM has made much progress in the realm of maintenance, but little on operational safety assessment issue. Current existing operational safety assessment methods commonly work at subsystem level, i.e. without safety information exchange amongst related subsystems, and do not consider environmental factors. This paper therefore discusses the issues around operational safety assessment in aviation industry.
2015-09-15
Technical Paper
2015-01-2619
Karl-Otto Strömberg, Stefan Borgenvall, Mohamed Loukil, Bertrand Noharet, Carola Sterner, Magnus Lindblom, Orjan Festin
LWPT (Lightweight Production Technology) is today a well-established technology in the automotive industry. By introducing light weight fixtures manufactured from Carbon Fiber Reinforced Plastics (CFRP), new production processes have been developed in the automotive industry. This has resulted in increased productivity, reduced investment costs and increased flexibility. The next step is to introduce this technology in the aerospace industry. Aircraft components are complex and large products having small tolerance windows. Fixtures manufactured in FRP materials allow integration of health monitoring sensors directly into the structure. This means that information on displacements can be recorded both when the fixture is stationary, while work is being performed, as well as in a pulsed production line when the fixture is moving between the assembly stations.
2015-09-15
Technical Paper
2015-01-2486
Greg Kilchenstein, F. Matthew Juarez
ABSTRACT
2015-09-15
Technical Paper
2015-01-2583
James Hare, Shalabh Gupta, Nayeff Najjar, Paul D'Orlando, Rhonda Walthall
This paper addresses the issue of detecting and isolating faults in complex networked systems. Complex Networked Systems typically contain multiple subsystems, components, and sensors interconnected through feedback control and thermal couplings. When a fault occurs in a component of a complex networked system, the effects of the fault may cause offnominal operations in other components due to fluctuations in their input signals. Health monitoring algorithms developed in literature typically result in false alarms during these scenarios since the data observed through sensor measurements are showing unhealthy characteristics even though the components are performing correctly given their offnominal input signals. This paper proposes a System Level Isolation and DEtection (SLIDE) algorithm that will detect and isolate faults occurring in multiple subsystems while reducing the computational complexity and minimizing false alarms.
2015-09-15
Technical Paper
2015-01-2587
Matthew Smith, Peter F. Sulcs, Rhonda Walthall, Mark Mosher, Gregory Kacprzynski
Aircraft System Health Management (ASHM) is a UTC developed web application that provides access to Aircraft Condition Monitoring Function (ACMF) reports and Flight Deck Effects (FDE) records for B787 and A320 a/c. The tool was built with a flexible architecture to field a range of off-board diagnostics and prognostics modules designed to transform an abundance of data into actionable and timely knowledge about fleet health. This paper describes the ASHM system architecture and implementation with a focus on “lessons learned” in applying diagnostic and prognostics algorithms to available fleet data. Key topics include managing data quality issues, design for cross-enterprise collaboration and defining a workable approach to testing, validating and deploying prognostics and diagnostics models with various degrees of complexity. A case study is provided related to fluid leak detection within an environmental control subsystem.
2015-09-15
Technical Paper
2015-01-2556
Thomas Rousselin, Guillaume Hubert, Didier Regis, Marc Gatti
The changes brought by the increasing integration density and the new technological trends have pushed the reliability at its limit. Safety analysis for critical system such as embedded electronics for avionics systems needs to take into account these changes. In this paper, we present the consequences on the Deep Sub-Micron (DSM) CMOS devices concerning their single event effect (SEE) sensitivity. We also propose a new modeling method in order to address these issues.
2015-09-15
Technical Paper
2015-01-2555
Ephraim Suhir
It has been lately established (see, e.g., [1]) that the continuing trend on miniaturization (Moore’s Law) in IC design and fabrication might have a negative impact on the device reliability, especially when it comes to deep submicron (DSM) technologies. These are characterized by etching thicknesses below 90nm. In order to understand and to quantify the physics underlying this phenomenon, it is natural to proceed from the experimental bathtub curve (BTC), an experimental reliability “passport” of a population of mass produced devices. As is known, this curve considers and reflects the combined effect of two irreversible processes: statistics-related mass-production process and reliability-physics-related degradation (aging) process. The first process results in a decreasing failure rate with time, while the second process leads to an increasing failure rate. It is this second process that should be of major concern to an IC designer and manufacturer.
2015-09-06
Technical Paper
2015-24-2530
Mohamed El Morsy, Gabriela Achtenova
A vehicle gearbox serves for torque and speed conversion with help of rotating elements. Therefor the gearbox experiences periodic excitation forces with a fundamental frequency following the rotation frequency. These excitation forces give rise to corresponding periodic response signals, i.e. signals having content at the fundamental (rotational) frequency and its harmonics. Order analysis is an analysis technique which is used to extract these harmonic orders from the response signals. This article intends to use the order tracking analysis for gearbox fault diagnosis under variable speed conditions to compare between healthy and faulty cases by using order extraction. Finally, determine maximum Root Mean Square (RMS) as severity index.
2015-09-06
Journal Article
2015-24-2465
George Bergeles, Jason Li, Lifeng Wang, Foivos Koukouvinis, Manolis Gavaises
Abstract Despite numerous research efforts, there is no reliable and widely accepted tool for the prediction of erosion prone material surfaces due to collapse of cavitation bubbles. In the present paper an Erosion Aggressiveness Index (EAI) is proposed, based on the pressure loads which develop on the material surface and the material yield stress. EAI depends on parameters of the liquid quality and includes the fourth power of the maximum bubble radius and the bubble size number density distribution. Both the newly proposed EAI and the Cavitation Aggressiveness Index (CAI), which has been previously proposed by the authors based on the total derivative of pressure at locations of bubble collapse (DP/Dt>0, Dα/Dt<0), are computed for a cavitating flow orifice, for which experimental and numerical results on material erosion have been published. The predicted surface area prone to cavitation damage, as shown by the CAI and EAI indexes, is correlated with the experiments.
2015-08-24
Book
Timothy C. King
A keen focus on operations, cost management, leadership, and customer service is presented in this book for fleets to thrive in today’s competitive business environment. Basic concepts and customer service fundamentals, along with integrated best practices, and business tools are fully described. This model can be applied by service groups of any size to achieve quality performance benefits for both the customer and the fleet-provider. Fleet Services: Redefining Success presents: • A back-to-basics approach that begins by redefining a fleet's customers to fully identify and provide customer-driven services. • A hierarchy for success that includes development of management goals and strategies to exceed customer expectations. • Best practices and associated business tool requirements that assure exceptional service and win-win results. • An innovative business model that maximizes opportunities and positive outcomes for fleet service providers.
2015-07-28
Standard
J1699/3_201507
The main purpose of this Recommended Practice is to verify that vehicles are capable of communicating a minimum subset of information, in accordance with the diagnostic test services specified in SAE J1979: E/E Diagnostic Test Modes, or the equivalent document ISO 15031-5: Communication Between Vehicle and External Equipment for Emissions-Related Diagnostics – Part 5: Emissions-related diagnostic services. Any software meeting these specifications will utilize the vehicle interface that is defined in SAE J2534, Recommended Practice for Pass-Thru Vehicle Programming.
2015-07-27
WIP Standard
AS6342
To develop Aerospace Standards (AS) for the minimum performance standards for external cargo and search and rescue hoists. The Aerospace Standards (AS) will lead to the development of a hoist Technical Standard Order (TSO); which will include the Minimum Operation Performance Standard (MOPS). which contain the design, qualification, test procedures and any other related tasks to support the hoist MOPS.
2015-07-23
Article
The companies have partnered to jointly develop and commercialize a next-generation exhaust system for heavy trucks that incorporates thermoelectric waste heat recovery.
2015-07-22
Standard
J2442_201507
This SAE Recommended Practice applies to road vehicles except motorcycles. It describes the commonalities of installation requirements for lighting and light signaling devices contained in the regulatory requirements and industry standards of North America, Japan, and the widely-adopted UNECE ("European") Regulations. It does not apply to installation of lighting and light signaling devices specific to special purpose vehicles, including but not limited to police, medical and other emergency or public service vehicles. This document does not carry force of law and does not replace regulatory requirements in effect at the time of application. It is subject to change to reflect additional experience, technical advances, and especially changes in government and industry documents used as references. Users of this document are advised to mind the applicable legal requirements in effect where their vehicles will be sold and registered.
2015-07-17
Standard
AS1284B
The test procedure and related limit value are intended to apply to fixed and mobile ground pressure fuel dispensing sytems and to aerial refueling tankers.
2015-07-13
Standard
AMS1453A
This specification covers a general purpose disinfectant in the form of a concentrated liquid to be used diluted in accordance with label instructions.
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