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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.
2015-09-29
Journal Article
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.
2015-09-23
Book
Tim 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.
2015-09-22
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
2015-01-2619
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
2015-01-2593
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
2015-01-2592
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
2015-01-2401
Michael Schmidt, Philipp Nguyen, Mirko Hornung
Abstract The projected uptick in world passenger traffic challenges the involved stakeholders 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, operate at their capacity limit and further extensions are difficult to realise. Delays due to late arrival of aircraft or less predictable ground operation processes disrupt the airport operations in a serious way. Various concepts improving the current turnaround processes have been presented thus far, whereby radical aircraft design changes have little chances for realisation in the short term. 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
2015-01-2473
Alessandro Ceruti, Alfredo Liverani, Piergiovanni Marzocca
Abstract 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
2015-01-2585
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
2015-01-2584
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
2015-01-2583
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
2015-01-2582
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
2015-01-2590
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
2015-01-2589
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
2015-01-2587
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, Alain Bensoussan, Johann Nicolics
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.
2015-09-15
Journal Article
2015-01-2397
Angelo C. Conner, Luis Rabelo
Abstract In planning, simulation models create microcosms, small universes that operate based on assumed principles. 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
Journal Article
2015-01-2440
Robert Moehle, Jason Clauss
Abstract Labor costs rank second only to fuel in expenses for commercial air transports. Labor issues are a growing concern in the airline industry, with an impending worldwide pilot shortage. One solution proposed and requested by some of the industry leaders is 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. Bureaucrats and the general public fall prey to isolated news stories that highlight pilot error and anchor their viewpoint on further regulating a two-person crew. 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. Technology is not the problem.
2015-09-15
Journal Article
2015-01-2545
Reza Ahmadi, Oliver Marquardt, Marc Riedlinger, Reinhard Reichel
Abstract Aircraft cabin systems, especially cabin management systems (CMS) have to cope with frequent cabin changes during their lifecycle. This includes not only layout rearrangements and technological upgrades during the service, but also extensive CMS customizations and product variations before aircraft delivery. Therefore it is inevitable for the CMS to be highly changeable and offer an easy and agile change process. Today's CMS solutions face this challenge with configurable system architectures. Although such architectures offer a vast change domain, they usually come with time consuming and error prone change processes. This paper introduces an adaptive avionics software architecture that enables the CMS to cope with cabin changes highly automatically and with minimal human interactions. The adaptation is performed during an on ground organization phase, in which system changes are detected and evaluated by the CMS itself.
2015-09-15
Technical Paper
2015-01-2486
Greg Kilchenstein, F. Matthew Juarez
Abstract The USAF T56 engine Program Office has adopted a unique maintenance approach which utilizes the concept of complete system reliability in order to optimize their cost of workscoping aircraft gas turbine engines. While classical Reliability Centered Maintenance (RCM) focuses on the actual reliability and failure modes representative of a particular system, its benefits are limited since it only describes individual system components9. The workscope cost optimization program provides the user with recommended optimal repair workscopes based on the underlying reliability and cost of repair options. This maintenance concept is based upon the methodology documented in SAE Aerospace Recommended Practice (ARP) JA6097, which is a “Best Practices Guide” established to provide direction in objectively determining which other maintenance to perform on a system when that system requires corrective action, with the goal of improving overall system reliability at the lowest possible cost.
2015-09-06
Technical Paper
2015-24-2530
Mohamed El Morsy, Gabriela Achtenova
Abstract A vehicle gearbox serves for torque and speed conversion with help of rotating elements. Therefore 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.
2015-09-01
Journal Article
2015-01-9001
Tarapong Sreenuch, Ian Jennions
For Integrated Vehicle Health Management (IVHM) technology to fully achieve its promise, there is a need for integration architecture to support interoperability between multiple vendors' IVHM components and insertion of new IVHM capabilities. To date there have been very limited studies on different approaches in integrating IVHM components. This paper presents design candidates for plug-and-play (PnP) IVHM architecture. The open standard based designs are derived from desired IVHM data flow characteristics and system configuration requirements. The designs and enabling middleware technologies are qualitatively and empirically evaluated for their adequacy and effectiveness. The qualitative assessment focuses on the implementation and system configuration based on different test scenarios. The empirical performance is measured in terms of latency (in both normal and intermittent network connections) and throughput.
2015-08-28
Standard
J1939/73_201508
SAE J1939-73 Diagnostics Application Layer defines the SAE J1939 messages to accomplish diagnostic services and identifies the diagnostic connector to be used for the vehicle service tool interface. Diagnostic messages (DMs) provide the utility needed when the vehicle is being repaired. Diagnostic messages are also used during vehicle operation by the networked electronic control modules to allow them to report diagnostic information and self-compensate as appropriate, based on information received. Diagnostic messages include services such as periodically broadcasting active diagnostic trouble codes, identifying operator diagnostic lamp status, reading or clearing diagnostic trouble codes, reading or writing control module memory, providing a security function, stopping/starting message broadcasts, reporting diagnostic readiness, monitoring engine parametric data, etc.
2015-08-28
Standard
J2064_201508
The Scope of SAE J2064 covers coupled hose assemblies intended for containing and circulating lubricant, liquid and gaseous R134a and/or R-1234yf refrigerant in automotive air-conditioning systems. Historically, requirements for the hose used in coupled automotive refrigerant air conditioning assemblies was included in SAE J2064. SAE J2064 has been changed to establish the requirements for factory and field coupled hose assemblies. SAE J3062 has been issued to define requirements for the hose used in these assemblies into its own standard. SAE J2064 also provides the necessary values used in SAE J2727 Mobile Air Conditioning System Refrigerant Emission charts for R-134a and R-1234yf. The certified coupling of MAC hose assemblies is required in meeting certain regulatory requirements.   A hose which has met the requirements of SAE J3062 and certified in J2911 must be used as part of the coupled assembly.
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