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Viewing 61 to 90 of 4781
2016-04-05
Journal Article
2016-01-0075
Steven Holland, Tim Felke, Luis Hernandez, Robab Safa-Bakhsh, Matthew A. Wuensch
Abstract Health Ready Components are essential to unlocking the potential of Integrated Vehicle Health Management (IVHM) as it relates to real-time diagnosis and prognosis in order to achieve lower maintenance costs, greater asset availability, reliability and safety. IVHM results in reduced maintenance costs by providing more accurate fault isolation and repair guidance. IVHM results in greater asset availability, reliability and safety by recommending preventative maintenance and by identifying anomalous behavior indicative of degraded functionality prior to detection of the fault by other detection mechanisms. The cost, complexity and effectiveness of the IVHM system design, deployment and support depend, to a great extent, on the degree to which components and subsystems provide the run-time data needed by IVHM and the design time semantic data to allow IVHM to interpret those messages.
2016-04-05
Journal Article
2016-01-0269
Zhigang Wei, Michael Start, Jason Hamilton, Limin Luo
Durability and reliability performance is one of the most important concerns for vehicle components and systems, which experience cyclic fatigue loadings and may eventually fail over time. Durability and reliability assessment and associated product validation require effective and robust testing methods. Several testing methods are available and among them, three basic testing methods are widely used: life testing, binomial testing (bogey testing), and degradation testing. In fact, their commonalities, differences, and relationships have not been clearly defined and fully understood. Therefore, the maximum potential of these testing methods to generate efficient, optimized, and cost-effective testing plans, consistent results, and meaningful results interpretation have been significantly limited. In this paper, a unified framework for representing these testing methods and conducting reliability analysis in a single damage-cycle (D-N) diagram is provided.
2016-04-05
Technical Paper
2016-01-0684
Shinji Matsuo, Eiji Ikeda, Yoshiaki Ito, Hiroyuki Nishiura
Abstract The engine in the new fourth generation Prius carries over the same basic structure as the 2ZR-FXE used in the third generation and incorporates various refinements to enhance fuel efficiency. Called the ESTEC 2ZR-FXE, the new engine incorporates various fuel efficient technologies to improve combustion characteristics, knocking, and heat management, while also reducing friction. As a result of this meticulous approach to enhancing fuel efficiency, the new engine is the first gasoline engine in the world to achieve a maximum thermal efficiency of 40%. This paper describes the fuel efficient technologies incorporated into this engine.
2016-04-05
Technical Paper
2016-01-0279
Chong Chen, Zhenfei Zhan, Jie Li, Yazhou Jiang, Helen Yu
Abstract To reduce the computational time of the iterations in robust design, meta-models are frequently utilized to approximate time-consuming computer aided engineering models. However, the bias of meta-model uncertainty largely affects the robustness of the prediction results, this uncertainty need to be addressed before design optimization. In this paper, an efficient uncertainty quantification method considering both model and parameter uncertainties is proposed. Firstly, the uncertainty of parameters are characterized by statistical distributions. The Bayesian inference is then performed to improve the predictive capabilities of the surrogate models, meanwhile, the model uncertainty can also be quantified in the form of variance. Monte Carlo sampling is finally utilized to quantify the compound uncertainties of model and parameter. Furthermore, the proposed uncertainty quantification method is used for robust design.
2016-04-05
Journal Article
2016-01-0639
Brian C. Kaul, Benjamin Lawler, Akram Zahdeh
Abstract Engine acoustics measured by microphones near the engine have been used in controlled laboratory settings for combustion feedback and even combustion phasing control, but the use of these techniques in a vehicle where many other noise sources exist is problematic. In this study, surface-mounted acoustic emissions sensors are embedded in the block of a 2.0L turbocharged GDI engine, and the signal is analyzed to identify useful feedback features. The use of acoustic emissions sensors, which have a very high frequency response and are commonly used for detecting material failures for health monitoring, including detecting gear pitting and ring scuffing on test stands, enables detection of acoustics both within the range of human hearing and in the ultrasonic spectrum. The high-speed acoustic time-domain data are synchronized with the crank-angle-domain combustion data to investigate the acoustic emissions response caused by various engine events.
2016-04-05
Journal Article
2016-01-0076
Mostafa Anwar Taie, Eman Magdy Moawad, Mohammed Diab, Mohamed ElHelw
Abstract New challenges and complexities are continuously increasing in advanced driver assistance systems (ADAS) development (e.g. active safety, driver assistant and autonomous vehicle systems). Therefore, the health management of ADAS’ components needs special improvements. Since software contribution in ADAS’ development is increasing significantly, remote diagnosis and maintenance for ADAS become more important. Furthermore, it is highly recommended to predict the remaining useful life (RUL) for the prognosis of ADAS’ safety critical components; e.g. (Ultrasonic, Cameras, Radar, LIDAR). This paper presents a remote diagnosis, maintenance and prognosis (RDMP) framework for ADAS, which can be used during development phase and mainly after production. An overview of RDMP framework’s elements is explained to demonstrate how/when this framework is connected to database servers and remote analysis servers.
2016-04-05
Technical Paper
2016-01-0329
Piyush Bubna, Michael P. Humbert, Marc Wiseman, Enrico Manes
Abstract Conventional car manufacturing is extremely capital and energy-intensive. Due to these limitations, major auto manufacturers produce very similar, if not virtually identical, vehicles at very large volumes. This limits potential customization for different users and acts as a barrier to entry for new companies or production techniques. Better understanding of the barriers for low volume production and possible solutions with innovative production techniques is crucial for making low volume vehicles viable and accelerating the adoption of new production techniques and lightweight materials into the competitive marketplace. Additive manufacturing can enable innovative design with minimal capital investment in tooling and hence should be ideal for low and perhaps high volume parts. For this reason, it was desired to evaluate potential opportunities in manufacturing automotive parts with additive techniques.
2016-03-14
Journal Article
2016-01-9151
Somnath Sengupta, Alok Deb, Siddhartha Mukhopadhyay
Abstract Model based approaches for engine fault diagnosis mostly address the faults external to cylinder since they predominantly use simplified averaged models which do not capture within cycle dynamics. Hence, by using an instantaneous engine model which distinctly characterizes the cylinder’s modes, the events occurring within the cycle can be captured. The events happening across various modes and the engine subsystems can be due to normal operation or faults whose symptoms can be seen as features. In this work, which involves detection and classification of faults occurring in cylinders, is carried out in simulation environment, where, a Kalman filter for state estimation incorporating a nominal instantaneous mode based engine model is considered. Using this estimator as base, faults occurring repetitively (every cycle) are addressed whose features are seen across relevant modes of a cycle.
2015-11-17
Technical Paper
2015-32-0748
Nobuyuki Kawahara, Shota Hashimoto, Eiji Tomita
The objective of this study is to investigate the initial flame propagation characteristics of turbulent flame in an engine cylinder through time-series analysis of radical emissions. A spark plug with optical fiber was developed in this study. The plug sensor is M12 type that makes it possible to mount in practical engine. The spark plug sensor can detect radical emissions in time-resolved spectra through time-series spectroscopic measurement. In this spectra, some kinds of radical emissions such as OH*(306nm), CH*(431nm) and C2*(517nm) based on principle of chemiluminescence are observed. In this study, the spark plug sensor was applied to both compression-expansion machine (CEM) and practical engine. As a result of CEM with bottom viewed high-speed camera, three kinds of spectra could be detected.
2015-11-17
Technical Paper
2015-32-0783
Yong Fu Syu, Jia Siou Wu, Jhih Si Syu, Bo-Chiuan Chen, Yuh-Yih Wu
In this paper, the off-line analysis method is applied to develop three-way catalytic converter (TWC) diagnostic strategy including oxygen sensor (O2 sensor) diagnostic strategy with common narrow band oxygen sensor (EGO sensor) in Matlab/Simulink software. Moreover, Mototron ECU (Engine Control Unit) is used for monitoring catalyst deterioration. However, aged catalyst is difficult to possess so the different catalytic conversion efficiency (CCE) is simulated by using exhaust by-pass valve. The CEC (China Engine Corporation) 1L V2, four stroke, water-cooled engine is selected as target engine to conduct engine dynamometer test. After making sure O2 sensor operates normally, the catalyst diagnostic strategy test is executed. The experimental result shows that the catalyst deterioration accurately can be detected when the failure phenomenon takes place.
2015-11-17
Technical Paper
2015-32-0843
Marek Lajda, Sebastian Hook, Nikolai Reimgen
During the start-up phase of machines it can happen that tools are inadvertently rotating, which is caused by the half-throttle setting. Due to the starting throttle locking mechanism, the engine's rotational speed is above the engagement speed of the tool (for example the chain of a chain saw). This article describes the software algorithms developed by PRUFREX that are able to prevent rotation of the tool upon machine start at idle. The patented software solution is able to differentiate between start behavior with and without a starting throttle locking mechanism based on the machine's speed and time information and, as a result, can identify or estimate the position of the throttle valve. The effect of the algorithms is the switch-over between different ignition curves that are stored in the microcontroller-operated ignition modules. This includes a provision in the start ignition curve that prevents the tool from rotating.
2015-10-01
Journal Article
2015-01-9019
Jean-Baptiste Gallo, Robert L. Russell, Kent Johnson, Thomas Durbin
Abstract With funding from the California Energy Commission, the California Hybrid, Efficient and Advanced Truck Research Center, contracted with the University of California, Riverside's College of Engineering to evaluate the performance of a Class 5 battery electric urban delivery vehicle over two standardized driving cycles and a steady state range test on a chassis dynamometer. The test vehicle, a Smith Electric Newton Step Van, was equipped with a proprietary data acquisition system which was set to record a wide variety of vehicle parameters at a 1 Hz sampling period. In addition, the chassis dynamometer was set to measure and record additional parameters. Lastly, a portable J1772 EVSE recorded both grid energy and power at 15-minute intervals. This project provides a controlled test evaluation of the Smith Electric Newton Step Van.
2015-09-29
Technical Paper
2015-01-2728
Paul C. Cain
Abstract OEM benefit: Vehicle manufacturers desire continuous feedback in monitoring key safety related sub-assemblies. In this application, engineers are calculating the remaining brake pad life by continuously 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 expenses in earthmoving equipment are cost prohibitive. Today, this technology allows OEM's to have high confidence, continuous feedback on this critical vehicle safety feature, avoiding expensive, unplanned repairs and to improve field “up time” performance. Application challenge: to develop 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 environment typical of large construction (earthmoving) vehicles.
2015-09-29
Journal Article
2015-01-2846
Chunshan Li, Guoying Chen, Changfu Zong, Wenchao Liu
Abstract This paper presents a fault-tolerant control (FTC) algorithm for four-wheel independently driven and steered (4WID/4WIS) electric vehicle. The Extended Kalman Filter (EKF) algorithm is utilized in the fault detection (FD) module so as to estimate the in-wheel motor parameters, which could detect parameter variations caused by in-wheel motor fault. A motion controller based on sliding mode control (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/moments 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 FD module diagnoses the actuator failures first.
2015-09-29
Technical Paper
2015-01-2879
Evandro Silva
Abstract 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 the heavy duty trucks systems. 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, as the 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.
2015-09-22
Technical Paper
2015-36-0281
Marcelo Vandresen, James Silveira, Milton Pereira, Richard Chaplin, Gustavo Fernandes
Abstract Integrated controls for commercial dynamometers do not have appropriate characteristics to perform research and teaching tasks. These are developed to perform quick tests and its logic is prepared to obtaining the information in accordance with the technical standards. This way, the use for research is hindered because it does not have an interface that allows a refinement to the desired data ranges, t data sampling and the type of load that is applied. Its use for teaching is limited because these "standard" controls does not allow to analyze or to determine engines characteristics that are not covered through tests specified by the standards, so the use of this tool as an important part in professional training formed by the institution.
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
2015-01-2486
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.
2015-09-15
Technical Paper
2015-01-2584
Andrew Dickerson, Ravi Rajamani, Mike Boost, John Jackson
Abstract A high fidelity system for estimating the remaining useful life (RUL) for Li-ion batteries for aerospace applications is presented. The system employs particle filtering coupled with outlier detection to predict RUL. Calculations of RUL are based on autonomous measurements of the battery state-of-health by onboard electronics. Predictions for RUL are fed into a maintenance advisor which allows operators to more effectively plan battery removal. The RUL algorithm has been exercised under stressful conditions to assert robustness.
2015-09-15
Technical Paper
2015-01-2583
James Hare, Shalabh Gupta, Nayeff Najjar, Paul D'Orlando, Rhonda Walthall
Abstract This paper addresses the issues of Fault Detection and Isolation (FDI) in complex networked systems such as the Environmental Control System (ECS) of an aircraft. The ECS controls and supplies pressurized air to the aircraft and consists of multiple subsystems that in turn consist of interconnected components, heterogeneous sensing devices, and feedback controllers. These complex interconnections and feedback control loops make fault detection and isolation a very challenging task in the ECS. For example, a faulty component yields off-nominal outputs which are inputs to the other coupled components. This coupling leads to off-nominal outputs from otherwise healthy components, thus causing unwanted false-alarms. Secondly, due to off-nominal inputs, the healthy components are driven beyond their normal operating conditions, leading to cascading failures.
2015-09-15
Technical Paper
2015-01-2585
Tuur Benoit, Yves Lemmens, Wim Desmet PhD
Abstract 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. A high-fidelity aeroelastic multi-body model of a fixed-wing large passenger aircraft is presented, suitable for the monitoring of landing maneuvers. The model contains a modally reduced flexible airframe and aerodynamic forces modeled with a doublet-lattice method. In addition, detailed multi-body models of the nose and main landing gear are attached to the flexible structure, allowing to accurately capture the loads during a hard landing event. It is expected that this approach will make way for embedding non-linear multi-body models, with a high number of degrees of freedom, in state estimation algorithms, and hence improve health monitoring applications.
2015-09-15
Technical Paper
2015-01-2592
Joao Pedro Malere, Wlamir Olivares Loesch Vianna
Abstract 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
Abstract In the past few decades the number of airplanes has increased dramatically and aircraft systems have become increasingly more complex. Under these conditions, the next generation of airplanes will undergo substantial changes and will make significant technical progress to improve operational safety. 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 and operation, but little on safety assessment. This paper discusses the issues around how IVHM could be used to aid the operational safety assessment in the aviation industry. Special attention is paid to existing safety assessment methods, and some challenges and promising research directions are highlighted.
2015-09-15
Technical Paper
2015-01-2619
Karl-Otto Strömberg, Stefan Borgenvall, Mohamed Loukil, Bertrand Noharet, Carola Sterner, Magnus Lindblom, Orjan Festin
Abstract Lightweight Production Technology (LWPT) is today a well-established technology in the automotive industry. By introducing light weight fixtures manufactured from Carbon Fiber Reinforced Plastics (CFRP) in aeronautical applications, new challenges as well as possibilities of in-situ health monitoring emerges. The present paper present results from experimental investigations using optical fibers with multiplex Bragg gratings (FBG) as strain gauges in an industrial CFRP fixture. Fixtures were manufactured of laminates made from CFRP. Measurements have been performed on a single CFRP beam with dimensions (8000 × 500 × 500 mm), used as a structural part in a larger assembly (9000 × 4000mm). The optical fibers were placed in between two laminates on two sides of the beam. The measurement data from the FBGs were compared and correlated to the measured displacements of the beam and the applied loads.
2015-09-15
Technical Paper
2015-01-2555
Ephraim Suhir, Alain Bensoussan, Johann Nicolics
There is a concern that the continuing trend on miniaturization (Moore's law) in IC design and fabrication might have a negative impact on the device reliability. To understand and to possibly quantify the physics underlying this concern and phenomenon, it is natural to proceed from the experimental bathtub curve (BTC) - reliability “passport” of the device. This curve reflects the combined effect of two major irreversible governing processes: statistics-related mass-production process that results in a decreasing failure rate with time, and reliability-physics-related degradation (aging) process that leads to an increasing failure rate. It is the latter process that is of major concern of a device designer and manufacturer. The statistical process can be evaluated theoretically, using a rather simple predictive model.
2015-09-15
Technical Paper
2015-01-2587
Matthew Smith, Peter F. Sulcs, Rhonda Walthall, Mark Mosher, Gregory Kacprzynski
Abstract The Aircraft System Health Management (ASHM) tool is a UTC developed web application that provides access to Aircraft Condition Monitoring Function (ACMF) reports and Flight Deck Effects (FDE) records for Boeing 787®, A320®, and A380® aircraft. 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 system architecture and implementation with a focus on “lessons learned” in applying diagnostic and prognostics algorithms to available fleet data. Key topics include ensuring analytic robustness, 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
2015-01-2593
Jonathan L. Geisheimer, Michael Wabs, Carlos Carvalho
Abstract Time Domain Reflectometery (TDR) is a Radio Frequency (RF) technology that has been used for many years to find cable breaks and measure fluid levels in industrial processes. The technology uses picosecond length pulses and the associated reflections off the fluid surface in a time of flight measurement to determine fluid height. TDR signals have additional information that can be processed and utilized for Integrated Vehicle Health Management (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 the 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, which can be used to identify mis-fueling situations, contaminants in the fluid, and potentially other fluid health properties.
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
2015-01-2582
Andre Silva, Nayeff Najjar, Shalabh Gupta, Paul D'Orlando, Rhonda Walthall
Abstract The Environmental Control System (ECS) of an aircraft provides thermal and pressure control of the engine bleed air for comfort of the crew members and passengers onboard. For safe and reliable operation of the ECS under complex operating environments, it is critical to detect and diagnose performance degradations in the system during early phases of fault evolution. One of the critical components of the ECS is the heat exchanger, which ensures proper cooling of the engine bleed air. This paper presents a wavelet-based fouling diagnosis approach for the heat exchanger.
2015-09-15
Technical Paper
2015-01-2556
Thomas Rousselin, Guillaume Hubert, Didier Regis, Marc Gatti
Abstract 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.
Viewing 61 to 90 of 4781